Trivia: The strange incantation heard at the beginning of the orgy scene is a fragment of a Romanian Orthodox Church sermon played backwards. If you play it backwards you'll notice that there are two main voices (in the movie is supposed to be only one - the voice of the "great priest") and a choir.
Trivia: Christiane Kubrick, Stanley's wife, has a cameo as the woman sitting behind Dr. Harford at Café Sonata.
Trivia: The actor who played Nick Nightingale (Dr. William 'Bill' Harford's medical school dropout friend), played a medical school dropout in "Gross Anatomy" (1989).
Trivia: The room of the morgue visited by Bill in this film is in wing C, room 114 - a reference to C-114 which was name of the decoding machine in Kubrick's film "Dr. Strangelove".
Trivia: During the scene where Tom Cruise is talking to Nick at the Sonata Cafe, you can see the director Stanley Kubrick sitting at a nearby table.
Trivia: Katharina Kubrick, the daughter of Stanley Kubrick, has a cameo at the doctor's office. The boy is her son, Alex.
Trivia: During production, Stanley Kubrick filmed 95 takes of Tom Cruise walking through a doorway.
Trivia: Kubrick pushed Sydney Pollack to his limits while filming Eyes Wide Shut. Pollack asked how Kubrick wanted him to walk across a room to answer a door. Kubrick said "I don't know, you decide'. Pollack kept trying different ways for the next two days, waiting for Kubrick to approve. Eventually, exhausted, Pollack said he was satisfied, and Kubrick replied 'I wondered how much longer it would take you'.
Chosen answer: I think someone from the freaky orgy broke in and put the mask on the pillow to warn Cruise's character to keep his mouth shut. That's why Cruise's character is so upset-they got into his home and his safe.
I always assumed that she was a member of the orgy party. She was letting him know that she was there.
No, she wasn't.