Sexual objectification is a social or cultural state of perception that excludes an individual's agency and unique personhood in order to frame them as an object that exists to sexually pleasure others. This state is also commonly referred to as as being a sex object, and can occur to an entire body, or to individual body parts (breasts, waistline, butt, etc.) that are commodified and de-personalized.
Common properties of sexually objectified bodies
Variations and combinations of these properties exist both inside and outside media, but these properties are commonly applied to images of objectified bodies. Then, actual people find themselves held to this standard and regarded as sex objects with these properties. This is by no means a complete list, but a simple and general list of some of the most common qualities objectified bodies are given.
- Objectified bodies are interchangable, not individual. Any objectified body can be replaced by another objectified body, without regard to the actual subject's identity and importance. Bodies that are treated as sex objects are actually harder for people to match up with individual faces and identities . With trends in photo editing, the actual features of even models are distorted and normalized into a sexually-appealing standard. In extreme cases, a woman may even be a stand-in for another object, often one being sold, such as a car or a beer brand. In media production, the idea of the sexy lamp test is related.
- Objectified bodies are often considered disposable. Meaning, because they are objects, they can be assaulted, thrown away, used, abused, or otherwise discarded to replace with a "new" one.
- Objectified bodies are modular. Meaning, parts are distinct objects as much as the whole, and one can stand in for all of them, or can be exchanged for any other part. Referring to someone as "A hot piece of ass," is a spoken case. In media and advertising, women may be represented by just one sexualized part such as the breasts, legs, or butt, with the face obscured or even cut out of the frame entirely. Celebrities may find their heads photoshopped onto another person's body, and many marketed media images are actually composites of many different photographs. Cultural trends in fitness and exercise that promise "spot reduction" or to improve just various body regions of sexual fixation are related.
- Objectified bodies are defined by their sexual availability and desirability over any other characteristic. Trends in advertising feature objectified bodies (mostly women) in various situations where they cannot consent (drunk, unconscious, even dead) or are assumed to already have consented regardless of the circumstances.
- Objectified bodies are often framed as commodities. If a body is pictured as being able to be bought and sold, without agency of its own, implying sex appeal is what is for sale, sexual objectification is at work.
- Objectified bodies are tools for another person's pleasure, not their own sexual agency. They are a fantasy for what the media assumes the consumer is, not a depiction of the character or image's own sexuality or needs. This may take the form of a direct sexual power fantasy ("this woman is desirable for heterosexual cis men") or a secondary vicarious fantasy ("You too could be as desirable to heterosexual cis men as this image.")
- Objectified bodies can be distorted or exaggerated to appeal to a target audience. Very thin models may have ribs or signs of emaciation airbrushed out of their pictures, imparting an illusion of health. Waistlines may be distorted to render them smaller than most humans could reach healthily. Breasts, buttocks and other parts may be increased in size. Drawn or digital images may be twisted into difficult or impossible poses to display more sexualized body parts at once, sometimes to unsettling effect if isolated and identified. 
Objectification and empowerment
Because sexual expression is often equated with empowerment in contemporary western culture, sexual objectification is often confused with free sexual expression. However, because of the principles above, the state of being a sex object involves the removal of personhood and agency, not the empowerment of a person or increase in agency. While in many cultures strict modesty codes have been relaxed and women's sexuality is less taboo, misogyny adapts to the times and in western culture can disguise itself as "strong" women that falsely demonstrate power by being combative and "tough" rather than self-motivated, and/or demonstrate sexuality by being appealing to others rather than being open about what is appealing to themselves. This is one criticism of the sex-positive movement, that contemporary women's sexuality is often conflated with images of being sexually available to men, and that just being able to be sexual is not a victory in a culture that buys and sells sexually objectified images of human bodies.
A very simple, extreme example of this principle can be seen in media and costuming that wants to depict a woman warrior, yet cannot resist including impractical or unreasonable features that imply her sexual availability. A professional soldier, for example, might be pictured wearing a sleek hip-hugging catsuit while her male peers don protective gear, with little explanation. Body armor sometimes is not pictured to cover the whole body or leaves vulnerable parts uncovered, where male characters almost never are pictured with little windows to their crotch, pecs, or butt in what is supposed to be a serious combat kit. Despite protests and actual demonstrations of their real-life dysfunction, these design features continue to go unjustified in media  with very few male characters dressing equivalently or being framed in similar ways.
This extreme example is evidence that while images of "powerful" women are often present, they are very often also controlled by a straight, cis, male norm that mandates a female character or image's importance is useless without (exaggerated) sex appeal to straight males. This manifests in tangible, real-world ways; the fashion industry genders products often by removing utility, pockets, or functionality from women's clothing for the sake of making it more appealing to the male gaze. Furthermore, what society presents as "equivalent" levels or standards of dress for men and women are not equal in functionality, price, or cultural consideration, because women wearing their chosen outfits are objectified and judged as objects rather than people wearing objects. Very often, the success of a woman is considered linked to the cut of her clothes, as well as her body shape, size, and appeal to cisnormative male-catering gender norms with celebrities and even female politicians being asked about their diet or their dress's designer over important questions their male colleagues receive.
Sexual objectification and gender
Women are the most common victims of sexual objectification, varying with intersection with race and the trans community. However, certain other demographics may be sexually objectified by equating them with women, such as some gay men when they are regarded as taking a more "feminine" role, or to a limited extent when they are sexualized by other men in the stead of female targets.
While many men are depicted exaggerated or distorted, it's often a power fantasy (more muscular, more affluent, more 'handsome') for the assumed-male consumer or viewer themselves, rather than sexual objectification. An exception is possibly the stereotype of black men as oversexed or sexually threatening (especially in the U.S.A), which relates back to standards codified during periods of enslavement of the black diaspora when black people were literally objectified: as slaves.
Other genders have different relationships with sexual objectification, ones that often relate back to how feminine contemporary culture considers them. Sexual objectification can be considered a facet of femmephobia, or oppression of femininity itself, independent of the women that it is equated with.
Effects of objectification
Sexual objectification induces low self-esteem, body image problems, and various eating disorders. Eating disorders, especially anorexia, are the most lethal mental illnesses in the world and are often connected to sexual objectification and feelings of inability to control one's body.  While the greatest impact is on women, who by-gender (with variation across intersections) are the most objectified demographic, many men also suffer from eating disorders in order to meet standards of sexual attractiveness and availability.
Other effects include the normalization and casual acceptance of sexual violence and abuse towards women, and the concept that an objectified body is a "reward" or an entitlement for another person, usually a man.
Objectification not only manifests in mental health disorders but also manifests in behavioral tics and highly socialized forms of body monitoring that can impede a person's daily life. The concept that one's body is there for other people to enjoy before oneself is the crux of phenomenons such as spectatoring, or third-person scrutiny and self-policing during sex, hindering personal enjoyment of even a consensual good time. On average, women engage in forms of body monitoring ("Where is the light? Am I sitting correctly? Who's looking at me? Where is my fat sticking out? Are my legs shaved?") about ten times in five minutes. This figure is not confirmed for specific intersections of women (black women, trans women, etc.) but it's likely that the farther away from the beauty standard or social acceptance for womanhood, the less work privilege can do to assure women that they are represented, sexy, and acceptable. It's not an advantage to be considered a sex object, however, but it is a position of (perhaps disturbing) hierarchy to be considered more sexy or a superior object by dominant social classes and intersections.
Sexual objectification vs. sexual representation
Sexual Objectification is harmful, because it does not represent the sexuality of actual subjects but the sexual expectations of a target audience. However,sexuality itself is an important facet of human identity and should not go undepicted or unrealized in our media and our lives. While some fictional works can deconstruct or invoke sexual objectification deliberately to make a point about it or draw attention to the practice, much of media, and much of the culture that is supported by that media, unironically objectifies women and some other genders. Traits of sexual beings that keep their agency include:
- Variation in sexuality: in orientation, knowledge and experience, and strength of desire. Sexual beings differ greatly, and if they desire to appeal to others (or not!), it is their own wishes rather than the desire of a creator, marketer, or audience.
- Aversion of stereotypes. Stereotypes are one way that real people are commodified and their images and real sexualities traded upon. "Spicy Latina," "Sassy Black Woman," and "Demure Asian" are inherently racist as well as sexist, for example.
- Whole, unique bodies instead of combinations of parts. Body acceptance and representation of a wide variety of body shapes and types as normal, sexual, appealing, and healthy is key to depicting beings with sexuality rather than collections of parts engineered to appeal to a certain target audience.
- Variation in gender and expression itself. Without depicting a wide range of genders and gender expressions as acceptable, real people who may not fit cisnormative standards are excluded.
- Able to give and withhold consent, as well as change its terms or revoke it at any time during a sexual encounter.
- Able to make their own expressive choices, rather than being a doll or model that is dressed or framed by others.
- Sexual Objectification (Part 1): What is It?, by Caroline Heldman
- Fantasy Armor and Lady Bits, by Ryan
- Women Fighters, a Tumblr
- Killing us Softly, a documentation of advertisement and sexual objectification and its effect on women of all ages.
- Objectification And... Men? Game journalist Jim Sterling explaining the difference between objectification and idealization regarding the portrayal of women and men in video games.
- 3 Ways To Tell The Difference Between Appreciation of Beauty and Sexual Objectification, by Jamie Utt
- When are people interchangeable sexual objects? The effect of gender and body type on sexual fungibility.
- Fantasy Armor and Lady Bits
- Deadliest Psychiatric Disorder: Anorexia. (Also has resources on bulimia)
- The Role of Body Surveillance, Body Shame, and Body Self-Consciousness during Sexual Activities in Women 's Sexual Experience
- Caroline Heldman, "The Sexy Lie"