The female identity has been harassed while the male identity was treated with respect. I don't see how anonymity has anything to do with it, the visitors were equally anonymous in both cases.
The reason only the female is harassed I think has a very simple explanation, only men behave this way.
Why the same men don’t behave e.g racist or otherwise harassing the male identity can’t say. Best guess there is that these men are simply threatened by women, especially those that are attractive or successful. But I’m way out of my comfort zone of even man-guessing now.
I didn’t intend to detract from the fact that these men are assholes or say sexism isn’t the issue here.