Monster in the Playhouse - S1-E9
Revealing mistake: As the monster hops from behind the snack island, the actor's white shoes can be seen for a moment. (00:30:00)
Monster in the Playhouse - S1-E9
Revealing mistake: As Reba the Mail Person exits the Playhouse, she goes past the window, and you can see her exit the sound stage through a door painted the same as the background.