Everyone's already "cross dressing" - most of the female & make population are wearing jeans, trousers, hackers, sweaters, hoodies, trainers etc every day.
Not many women even wear dresses and skirts on an average day, and definitely not casual.
What they mean/do therefore is take a dressed up, "glamourous", made up, stereotypical, "sexy" aesthetic that is all about emphasising stereotypical femininity and making women look as far as possible from men; this started in good ol' Victorian times (was not actually the case before then); it's got a real element of objectifying women and fetishizing women and a part of it is usually wanting to be listed over and sometimes degraded. It's based on quite disturbing and objectifying views of women and what bring a woman & femininity is.
I therefore find it creepy.
Aesthetically I find it a massive turn off too.
I'm heterosexual and Im attracted to men looking like men (they can be dressed like Adam Ant, New Romantics, whoever; they're still looking like men..... Not men trying to look like a clichéd, "sexy" version of women.