>>119699529This is a phenomenon known as adaptational attractiveness, or "Hollywood Ugly", in which conventionally attractive people are portrayed in media as being ugly. Think The Princess Diaries, in which the audience is told beautiful celebrity woman Anne Hathaway is actually ugly with her glasses and curly hair, and only by removing those things can she be perceived as attractive. The trope can also be encountered in the Dreamworks classic "Small Soldiers" where Allan Abernathy(Played by Gregory Smith) is an unpopular dork, despite looking like the guy who shoves you into a locker and takes your lunch money.
In the case of Penny Proud in the Proud Family, it is made pretty clear in the show with the amount of boys thirsting after her despite her mother Trudy(Who I might add is fine as fuck) buying her unfashionable clothing, that Penny is generally regarded as quite desirable, and that her lack of success with romance has nothing to do with her lack of desirability, but her father's interference with her social life.
