The 22-year-old actress plays a criminal teen in the film, which is inspired by the burglaries of Hollywood socialites, reported Sun online.
"This is how much I hate myself in the movie: I don't think I am going to be able to watch it," she said.
Watson will be seen sporting ugg boots, a pink tracksuit and fake tattoos for the role.
"It is the first time I couldn't watch myself. This is what is so awesome about my job, to get into the shoes of someone I couldn't relate to," she added.
The film is being directed by Sofia Coppola and also stars Leslie Mann, Taissa Farmiga, Gavin Rossdale among others.