Although uncredited in the actual film credits, Cameron Diaz is listed in the credits for the movie-within-the-movie "The Amazon Games", which can be seen during the final voice class at the end of the film.
All the studio scenes were filmed at The Legendary Marc Graue Voice Over Studios in Burbank. In the movie you'll recognize Studio A, Studio 4, the hallways, reception area, kitchen and the upstairs entrance to Studio 3.
This is the second film in which Cameron Diaz has appeared that deals with movie trailers. In "The Holiday" (2006), her character runs a company that produces movie trailers. In this film, she has an uncredited role in the movie trailer for the film-within-the-film.