During Eeyore's birthday party, Piglet and Christopher Robin are the only ones shown without napkins around their necks. As the camera zooms out when Christopher Robin is thinking about Pooh sticks, Piglet has a napkin around his neck.
In the last picture of Pooh eating the last of the honey in the pot that he gives to Eeyore for his birthday, a spot of honey is on his shirt. Then the spot vanishes when he smacks his lips and remembers what he needs to do for Eeyore.
The old wooden bridge's appearance frequently changes. It's first shown uneven, then it's level, and there are a few times when the bridge is shown uneven again.
In the beginning of the short, the book says "Winnie the Pooh and the Honey Tree" when the camera is zoomed out. However, once the book is about to open, you can see that the book title is changed to "Winnie-the-Pooh". Obviously, the opening scenes were reused and overdubbed.