While Emory starts serving his "depressed pasta" at the party, the rose in his teeth changes direction.
When Michael is on the phone with Alan, the chalkboard next to the phone goes from clean to dirty then back to clean.
The telephone in the living room is a 1A2 model for multiple lines with a hold function. Michael has at least 2 lines as noted in the action. The line cord to the phone is a standard cord for single-line phones. The 1A2 requires a larger line cord with more pairs of wires to operate both lines, lights on the phone and the hold function.