Continuity mistake: When Jerry is pretending to dance with the placecard mascots at the restaurant, the last mascot he dances with initially has red hair, but when the two pretend to skate on the mirror, her hair is now blonde.
Continuity mistake: Before Jerry enters the elevator in the hotel, there is nothing on the wall. When the elevator doors open at the floor in which it stops, a push button panel has suddenly appeared.
Continuity mistake: Before leaving for Manhattan, Jerry leaves a letter under Tom's paw. You can see that the letter has a large fold in the bottom left hand corner, but when we see the letter in the next shot, it now has a smaller fold.