This is one of what are called the "little houses". There are four of them around the building where the main shrine room is. They are for offerings that are made to the kings of each direction. You can see a little plaque with a picture of one of the kings, this one of the western direction, and the traditional offerings of water for drinking, water for washing, flowers, incense, a butterlamp, (the scented water offering is missing, maybe there wasn't room for it), food in the form of a small torma, and music, and also some small tormas on the upper level in the back.