As an isolated incident, it's charming. When it's every day of your life, it gets to be upsetting. Especially when past experiences have included more than on incident where the charming line was followed by anger and insults when it wasn't properly appreciated.

Ask your female friends if it's ever happened to them. I expect a large majority of them will be able to tell you a story.

Here's the best way I've been able to come up with, to get a feel for it. Suppose you have a nice watch. When somebody says, "Nice watch!", you say, "Thanks". But when you start meeting more than one person who won't stop talking about your watch, you get a little antsy. When somebody follows up with "Give me your fucking watch!" you start to think about leaving it at home some times.

Except that when you're a woman, you can never leave that at home.

This experience really isn't just about her. It's something practically all women experience. She seems to have just assumed her audience would share that context -- perhaps a side effect of being in academia.