Along Sunset Boulevard you will find a window advertising the services of Max's Classic Directing Academy. This isn't just some random sign for a random director. Rather, this is a reference to a classic Hollywood quote.
Appropriately enough, the window is a reference to the Hollywood classic, "Sunset Boulevard". The secret here is the motto of this academy, which is "Are you ready for your close-up?". That motto is a reference to a line in the film where Gloria Swanson's character, Norma Desmond, says that famous line at the end of Sunset Boulevard, "All right, Mr DeMille, I'm ready for my close up." In this case, Mr. DeMille refers to the character of Max von Mayerling, played by Erich von Stroheim, who is the director on Desmond's latest film.
For fans of the film Sunset Boulevard, there's one more reference to the film and it's in the Great Movie Ride where Norma Desmond says "We didn't need dialog, we had faces."