So, having read your tags, I have come to understand that you identify as asexual, and that this post is -- before anything else -- an extension of the dissatisfaction you feel with the current state of society regarding your ability to bear non-sexual body parts in public, for fear of being misconstrued as sexual.
With that said, this post engages in rhetoric I disagree with, and thus, I would like to articulate some counterpoints.
The primary argument of this post, if I have it right, is that people cannot discern the difference between neutral nudity, erotic art, and pornography. I feel as though your definitions belie the fact that you also don't seem to entirely understand the differences between erotic art and pornography that you are attempting to tease out.
Merriam Webster defines pornography as "the depiction of erotic behavior (as in pictures, movies, or writing) intended to cause sexual excitement", and I feel as though that provides a more fertile framework for discourse, as it does not attempt to box in the particulars of which erotic behaviours are described therein, and it does not attempt to discern which behaviours are erotic, or why. Your definition, on the other hand, is simply not attuned to material reality -- although you do go on to discuss what you consider to be edge cases / further nuance in your tags. I wish you had included that further nuance in the body of the post, in all honesty!
With that said, again having read your tags, I understand that your heavy slant toward visual media is, in fact, a result of this post being an examination of your grappling with being seen as a sexual being, and not, more fully, with the actual nature of what is pornographic and what isn't.
With regards to your definition of erotica, I return to Merriam Webster, who defines 'erotica' as a stub of 'erotic': "of, devoted to, or tending to arouse sexual love or desire", being "literary or artistic works having an erotic theme or quality". Your argument that "It's the implication more than the imagery but if you weren't a sexual person it could just be seen as risque fashion" is not something I see bearing fruit, and indeed, I believe that may be because of your misapplication of the word 'risque' in this context. To be 'risque' is to be sexual, in most English usage of the word. Beside the point, though. What you've said here is that 'if you weren't a sexual person', you would 'read' -- as it were -- erotic art is something other than sexual. I want to know more about what you are attempting to argue here. This is entirely inference on my part, but it sounds like what you are attempting to imply is that there is a 'sexual' (ie: vulgar) interpretation of any given work of erotica art, and a superior, 'non-sexual' (elevated) interpretation, accessible to those who do not approach the work with the intention of being sexually aroused by it.
With regards to your attempt to map meanings surrounding nudity, I believe that you do your argument a disservice by entirely forgoing a definition in favour of engaging exclusively in negation. When one hangs their hat entirely on oppositional definitions, they lose a valuable opportunity to discuss nuance. Nudity is: the neutral state of the human body, full stop, yes. And within the framework you've explored here, yes, a woman who is "just standing there" is neither erotic nor pornographic. The definitions up until this point have been you, OP, speaking to me, the reader, using second-person language: ie 'designed to arouse YOU', if 'YOU weren't a sexual person', etc. But, when we get to this section on nudity, it becomes about an as-yet-undiscussed "she". 'She' is a person, and 'you' are a Consumer Of Pornography. Why is the argument formatted this way?
Statues in Rome: So, this is one of those notorious 'subjective' art things you discuss in your conclusion. Part of the appeal of statuary such as this -- especially contemporary to the period -- was that it showed the beauty -- specifically the erotic, sexually attractive beauty -- of the human physique. The model for Discobolus -- figure below -- was considered very handsome -- very sexually attractive -- contemporary to the carving of this statue. In addition to that, he was an athlete, of course. Athleticism was a sexually attractive feature to artists and patrons of the arts during the Classical period. To argue otherwise is to attempt to obscure material reality.
Further, there are many examples of 'just a guy standing there' statuary that are -- in fact -- both created to honour gods and be sexually evocative in nature.
This is the fertility god, Priapus. Made famous by the modern affliction of 'priapism' -- as in, an erection that cannot be abated save by medical intervention -- who has, in Roman mythology, a permanent erection. This statue in particular has a pipe running through the phallus, such that it can be used as in a fountain.
"A woman taking shibari photos or wearing latex isn't porn, it's erotica. Pin up women are also a good example."
Do you yourself engage in shibari or latex fetish? I feel as though the mobilization of these particular subcultures in this particular argument is incongruous with how many members of these subcultures discuss themselves or discuss the pornography that they make or consume, and thus I am interested to know if this is an 'own voices' argument. I will not attempt to imply I have engaged in latex play in any material capacity, as that would be a lie, but from what I have read and observed, many latex fetishists engage in non-genital play. The presence or lack of genitals does not the pornographic / erotic binary make. Indeed, many people who discuss this subject in particular tend to discuss Erotica as a variety of pornographic art, instead of being something outside of the pornographic space. And to be clear, of course, an individual in their own home, unobserved, "wearing latex" is not porn.
With regards to pinups, I wholly disagree with you. What are you using as your definition of 'pinup'? Because it entirely depends on your angle here. The word 'pinup' refers to art or photography that people "pin up" on walls or in lockers. If we are working from a 1950s 'popular culture' definition, then the typical popular motifs are entirely clothed, demure women.
But, that would actually be a bit of a smoothing of the reality once more, as 'mature' pinups absolutely existed in the 50s as well.
But, if we are getting into pinups as they existed in the 1980s, we are discussing an entirely different planet artistically.
The first figure is certainly meant to be appreciated as sexually arousing, and so is the second figure, but both approach sexual stimulation from different angles of artistic expression.
"2 guys barebaking on a couch is porn"
Again, unfortunately, two guys barebacking on a couch is not always 'porn'. Heated Rivalry is a current, modern-setting television show which depicts "2 guys barebacking on a couch" in a non-pornographic fashion. It is certainly erotic, and meant to be hot / sexually stimulating, but it is not a work of pornographic art.
"Similarly a woman wearing shibari like in the last example also now having toys attached would seperate it from erotica to just being porn."
Let's discuss for a moment, the sexual politics of penetration as being 'the only real sex'. Why, when a 'woman' has the ability to penetrate, does she move from the 'erotica' box to the 'porn' box. She and her beloved wife -- my strawmen are lesbians -- could have just as much passionate lovemaking either way, no? Is it the fact that she now has a phallus, and thus has simulated externally prominent genitalia, which are perverse/more sexually explicit than a vulva? Is it that phalli are more sexual somehow than clitori? What is the distinction here? How long does a transgender man need to be on testosterone before his genitals become pornographic?
"But also, context matters for one, and it's not the artist fault YOU took it as porn. Definitions matter in order to protect the people making the art, from ppl that can easily manipulate all of someones art to just "porn" when it isn't, and possibly damaging the artist career by labeling it as such."
Context absolutely does matter, and so do definitions! I am compelled to argue, though, that saying anything is "just" porn delegitimizes an already highly maligned and stigmatized subject of artistic expression.
Here's where I agree with you: I agree that neutral human body parts should not be considered 'sexual' when being engaged in a neutral capacity. I agree with you that images of nude people are not inherently pornographic.
Where you and I differ is in your various articulations of art as a vehicle for sexual gratification.