After Dr. Kirby leaves, Beaver changes the lettering on the medical bag in his drawing from "M.D." to "MAD". In the next shot, the bag says "M.D." again.
When Ward joins the boys in their room to address Beaver's anxiety, Beaver's pillow shifts positions. In some shots, the top left corner is under his right ear, and bent forward. In other shots, the pillow is upright and Beaver's head is resting near its upper right corner.