Appearances do sometimes affect casting decisions though not always. Sometimes a pretty girl gets the role because of her talent (ex. Emma Roberts' characters are usually not emphasized on beauty but character), not because she is hot but sometimes a girl gets cast as such for being hot. In the movie "Love for Beginners" it starred both Rin Takanashi and Emi Takei. I could really say that while both are pretty, Emi Takei is more on the "cute side" than Rin Takanashi is on the blazing side. Compared to Ugly Betty which really needed all that annoying make-up and obviously artificial ugliness, Emi Takei (who I'd rate a lower beauty) is cast for the main role who is a geeky girl since it looks more convincing to do that outfit on Emi Takei than to that of Rin Takanashi who can be cast well as a Poison Ivy type seductress. Nothing wrong with portraying Rin Takanashi as a nerd though, provided if she were a nerd that gets lusted after like Belle is. The...
Some of my random thoughts from a hyperactive mind!