This is In Orbit, a hamster wheel 'house' with two sets of furniture (one for inside the wheel, one for out) that can be rotated by its two occupants walking simultaneously in opposite direction to access the various pieces of furniture. The wheel is aligned so both use identical pieces of furniture at the same time, so if you want to sleep but the other person wants to sit at the desk you're going to have to fight about it. Apparently two guys lived in the wheel for ten days straight, although I assume they took bathroom breaks because it doesn't look like there's a shitter module. Unless its hang your ass over the side and go to town, in which case I admire the oldschool approach. I peed out of an open car window once. At least I thought it was open. What I actually did was cause the power locks to short-circuit.
Keep going for a video.
Thanks to Andreas and pip, who want to live in a gerbil ball house. Same! Now roll me down the stairs.