 The voices of the unseen studio executives during the first  screenwriting scene (and the one later in the film) are all famous  directors, including Marshall, Garry (qv), Mazursky, Paul (qv),  Pollack, Sydney (qv), Reiner, Rob (qv), and Reiner, Carl (qv)  (although Carl is more famous for his comedic acting). All of these  directors are also known their occasional acting forays.