Rita Ora

She appears in the movie Harry Potter y el Prisionero de Azkaban (2004) in the background during the scene when Harry, Ron and Hermione attend professor Trelawney's divination class. Her character can be seen wearing a Gryffindor tie. She is not credited anywhere for this small role.

I never think too hard about a look. When you consider an outfit too much, that's when it goes wrong.