Though we may not have personally experienced it, I think many of us have at least witnessed the objectification of female bodies - particularly of nude or sexualized ones.
Perhaps you've seen a friend on social media post a sexy photo, one with her cleavage as the clear focal point, or where she's wearing very little clothing for whatever reason (maybe it's for an event, or maybe that's just what she felt like wearing for this photograph), and you can't help but notice a disturbing trend in the comments section. A trend of her male friends making very sexualized comments toward her. Some of these men are just there to drool over her, making the typical "nice legs, honey" comments. Some of these men make it clear that they've already imagined her in situations that she may not have even wanted to be in, saying "there are so many things I'd like to do to you". And while you may not see it directly, it may not come to you as a surprise when I say that some of these men have privately messaged her explicitly sexual comments, invitations, or dick pics as a result of this photograph that she publicly shared.
Because when a women represents herself as a sexual being, too many men see that as an invitation to began treating her as a sexual object, one whose humanity can be entirely drained away to serve only the purpose of their gratification.
And there are some people who don't really see this as a problem. They see the posting of photos like this, or a woman dressing in even-just-slightly revealing clothing, and they say "well, if she didn't want this kind of attention, then she shouldn't have done that in the first place". Personally, I disagree with this statement, however, and for a couple of reasons:
1) It ignores the fact that, maybe, she didn't dress or act this way for men.
Whenever people see a woman presenting themselves as a sexual being, they always seem to assume that she's doing it specifically for the purposes of the entire community of straight men, which feeds into this vicious cycle that I'm talking about. She's doing this for men, therefore it's alright for men to talk to her however they want or send her whatever pictures they feel comfortable.
But women don't necessarily have to have had men in mind to take a sexy photo or dress a specific way.
Maybe she just got a new outfit that she's pleased with, and she wanted to show it off.
Maybe she feels like she looks particularly pretty in that photograph.
Maybe representing herself in a sexualized manner makes her feel confident and powerful.
Maybe it has absolutely nothing to do with men at large - maybe she just wanted to wear that outfit today. Which makes catcalling, dick pics, and objectification completely unwarranted when you think about it that way. Imagine trying to show off a nice, new shirt that you bought, and the only responses you get are obvious come-ons and sexual advances from everyone, including people who you might not have even wanted to think about you that way.
And even if she is intentionally representing herself as a sexual being, that is only because many women are sexual beings. Women have desires and attractions, and if they feel comfortable expressing that in a public setting, then they should feel safe to do so without being hounded by men who only want to tell her the ways that she can gratify them.
A woman isn't 'inviting' anything by the way she dresses. She isn't an object who exists only for your pleasure - she is a human being who should be considered as much more complex and varied than that.
2) Sexual objectification doesn't just happen to women who are dressing or acting sexual.
The best example that I can think of that's been on many people's minds lately is breastfeeding. A woman's breasts are not, inherently, sexual objects. They are a part of her body, and sometimes, they can be used to feed small children. But many breastfeeding mothers have been forced into shame and seclusion directly because a part of their body that they cannot help having has been deemed sexual by other people.
I have heard from people who fear what might happen if a child walks by and witnesses a woman feeding her baby in a public space, as though the sight of a breast is a fearful thing that might contaminate the young and pure of heart. But at the end of the day, it is just a breast, just a part of the human body, and no child who sees one will be worse (or better) off for it. The only reason why people think of it as a dangerous and sexual thing is because they've decided that it's a dangerous and sexual thing.
The same thing is true for essentially all nudity. Nude photography, for example, is something that we've often been taught to view as fearful or inherently sexual. If one poses nude, then they are forced to take into consideration things like what people at work will think if they ever find out, or what their children will think if they ever stumble upon the pictures. But, a) nude photography does not inherently have to be sexual, and if you want evidence of that, I urge you to look up some of the late great Leonard Nimoy's work. Some of it is just celebrating the beauty that is the human form, and b) even if it is sexual, so what? Many of us are sexual beings, and what's so wrong with that? What about that is so fearful? I mean, yes, there are certain people in our lives who we may not want knowing that side of us, but if someone feels comfortable expressing it, then they should be allowed to without fear of being stripped of their humanity in the eyes of others because of it.
So I know that the question many men will be asking at this point is, "What is the appropriate way to respond then?" and, truth be told, I don't know if I can entirely give a blanket answer to this question, because a lot of it has to do with the individual - particularly, it depends on your relationship with the person as well as the setting. All that I can really say is that, if you are considering making a sexual comment toward someone, you need to take a second beforehand to ask yourself, is this warranted? Is my relationship to this person one where I am totally justified in responding to them in this manner, and is their behaviour suggesting that a sexual response is proper? A lot of this is something that is going to require judgement on your part, because it's difficult to broadly describe in which scenarios its appropriate and in which it isn't. After all, treating a woman as a sexual being, with her own sexual agency, is not a bad thing. It only becomes twisted and ugly when you treat her as a sexual object, with the expectation that she exists for and should be flattered by your pleasure.