How do they doobi Oobi?

My wife and I were wondering how they manage to show all the hands used for the various Oobi characters without getting the rest of the actors' bodies in the picture. We both figure it involves placing the sets above the actors' heads, so that they raise their hands to be level with the sets and their heads and bodies are thus below the frame. Where we differ in our speculation is that I'm guessing the actors are on their knees and the sets are maybe at the level of an average desk or table. My wife thinks the motions are too smooth for that and that the actors must be standing, so that the sets are high off the ground. Anybody know for sure?