Continuity mistake: When Porky is lighting the candles on the cake at the beginning of the cartoon, the position of the candles change between shots.
Continuity mistake: Before Mickey takes the bucket and leans out of the window to get some water, the lid of the coffee pot is closed. But after he has collected some water, the lid of the pot is now open.
Continuity mistake: When the St Bernard dog is preparing the drink for the frozen bird, he puts a cocktail stick with a piece of orange and a cherry into the glass, but when we see the dog holding the glass in the next shot, the cocktail stick has disappeared.
Continuity mistake: When Von Hamburger shows the producer the completed reel, it has a green spool and he puts it by the side of the producer's desk. Daffy then replaces it with his own film and you can see that the spool is light blue. The spool then becomes green again in the next shot.