This tent doesn't appear to work like the still you're thinking of. It's not designed to extract water from the ground. You apparently put dirty water on the "bottom layer", the heat from the sun evaporates the water and it condenses on the inside of the tent, where it rolls down to collection areas.

I wouldn't want to be in there while that's happening, but that's probably not the intent (heh) anyway. Looks like a dual purpose item... at night, it's a tent. During the day, it's a solar still. Kind of a neat idea, if he can pull it off.