No one was around so that I could ask about their tiny house they built. Perhaps it turned out too tiny. That is a propane hot water heater to the left of the door and probably an air conditioner above it. They have it blocked off for the winter.
On the other side is the inlet to fill a water tank and under the house I see an outlet for dumping black and grey water so it must have a toilet and sink. The green tent is your shower. On the roof I can just make out at least one solar panel for electricity.