>>40109839Because you only notice eyelashes on people when they're using make-up to exaggerate them, and they do that to make themselves more alluring. So noticeable eyelashes in drawings is essentially playing off that make-up shorthand for "Fuck me."
And because you're a dirty pokefucker having that increase of fuckable on something you want to fuck is not an additive effect, it's multiplicative. Trust me, I know, I want to fuck the shit out of Sneasel. 