In Miriam's office, a poster on the wall reads "REACH FOR THE STARS". The man depicted on the poster is the late astronomer, educator, and author Carl Sagan.
At approximately 7:04 - most of the graffiti shown are the names of the colorists who worked on the film.
At approximately 43:51 - the painting on the wall behind Aengus is a watercolor of the opening shot of the film.
The ice cream in the freezer is named "I Am Spartacrunch", referencing the oft-repeated line from Espartaco (1960).
Ethan, mocking his father Cyrus, says, "I could have been a contender." The quote is from Nido de ratas (1954), spoken by ex-prize fighter Terry Malloy (Marlon Brando).