I do question the mocking piece. Pointing at men and saying they look ridiculous in women's clothes, just reinforces the idea that some clothes are reserved some some sexes.
I don't think that's it. It's about the local man who's been known for years to have major MH issues, who now goes to buy chips each lunchtime dressed in fishnet tights, a mini skirt and black patent ankle boots with 6-inch heels with full make-up over heavy stubble. It's about the trans lesbian who turns up on a lesbian-only camping weekend in pink micro shorts, a strappy top and an M&S lady-fleece while all the lesbians are wearing cargo pants and men's shorts and walking boots and beanies.
I've never pointed or ridiculed, but when I first encountered chip shop man I certainly did a double take and maybe a quick nervous laugh, because this is not how 99% of women would present in the circumstances.