Even today, women are judged not on the facts of who they are, but by the image men (and women) create around them. They're already bullied and harassed for their virginity (or lack thereof), "body count" (real or perceived), promiscuity, their conformity to society's standards of beauty, and so on.

Nudes, especially those created specifically to objectify or harass, will harm women. It will harm their self image, it will harm their reputations, it will harm their careers (women are already being fired from jobs because of nude pictures of them on various websites).

People are not rational beings. We can know intellectually that a picture is probably a fake, and it won't change how it impacts us. Especially if it plays on our expectations. We tend to go with our first impression, even if it's later proven wrong.

See: "Biden was shown images of babies being beheaded." An image many of us still have in our mind, even though it was explicitly debunked.