Trials Pass Houses

Can someone explain what the "houses" are with the 2019 Trials pass? I clicked on one and it said that once chooses it could not be undone. Can someone provide a link or explain what choosing a house does? Are there rewards tied to picking one? Thank you in advance.
Best New

We're testing a new feature that gives the option to view discussion comments in chronological order. Some testers have pointed out situations in which they feel a linear view could be helpful, so we'd like see how you guys make use of it.

Report as:
Offensive Spam Harassment Incorrect Board