It isn't about vanity at all, that's why. The film makers themselves said it was supposed to be grungy, and un-KEPT See I can correct spelling as well. t: There is no vanity in the Joker. His looks are merely eccentric, theatrical, and flamboyant. He's not combing his hair, tucking in his shirts, wearing fadoras, dressing like a mobster. Afterall the Joker is highlighting the differences between himself and typical Gotham criminals from their underworld. That's why the second Joker does get concerned with his look (IE "hello beautiful") and sloppily moves his hair back ... it's supposed to be comical, because he is so disgusting looking.