To make a stocking stuffer for himself, the boy removes the stovepipe from the stove and connects it to his hanging sock. The boy then goes to bed, and in the background the sock has disappeared and the stovepipe is back in its original position, connected to the stove.
The boy removes a shoe and a sock, and hangs the sock on his wall. When he then climbs into bed, he has two shoes on again.
After he has used the cat to light up his Christmas tree bubbles, when the poor boy goes to remove the stovepipe, the long shot shows that the toy soldier is gone from the edge of his nightstand; however when he goes back to bed, the toy soldier is back sitting on its edge.
At the end, after he has eaten the drumstick and poured milk for the cat, the long shot shows that the pipe and sock are missing from the background, however they were right there when he opened up the big package, just a frame prior.