Continuity mistake: When Daffy demonstrates the knife sharpener, the spoon in the bowl next to the sharpener changes position between shots. There is also nothing on the side of the sharpener at first, but in the next shot the words "Knife Sharpener" have appeared.
Other mistake: When Daffy uses the elevator-like device to bring the second floor down to the first floor, there is a useless outside door on the second floor.
