Right, it's because they look ridiculous, I agree.
But...Why do we think they look ridiculous? What signifiers are they messing with? Why is the combo of boobs & beard supposed to be comical?
Woman with long hair and makeup in a man's suit: not funny. Possibly sexy?
Man with a beard in a woman's dress: comical.
Why? Because women aren't funny? Because she's claiming status by dressing as a man and he's sacrificing it by dressing as a woman?
If not that, then what do you think is happening when we laugh at men in womanface? I don't want to labour this point too much, because it'll get dull and a dozen people will roll in and tell me I'm overthinking it, but if my interpretation is wrong, it'd be great if someone could explain why, without saying "oh, it just is".