There are three houses on a hill. Each overlooks a different slope of the hill, but all are pretty close together. They seem to have been built all at the same time.
The first one is tiny, but full of little details. There are few rooms, and all of them are not spacious. The staircase is so steep and tiny that someone inexperienced can easily fall down. Yet everything there seems to have a meaning. A purpose. No single object has been left there without a specific purpose.
The second one is twice the size of the previous one. It's much more functional; bigger, better laid out. There are things in it, but they don't seem to be set in a particular order. Sure, they may have a purpose, but everything seems to be in a bit of a mess. It's just there.
The third house is enormous. There is so much space there. You get surprised by every room; by how big all of them are. There is space for everything, yet very few things are in this house. Very little furniture, no art or anything.
The three houses represent: ego, wisdom, and joy.
Which one is which?