It's simple. First, somebody would ask something like "How would you go about making a good-looking x?"
In this hypothetical situation, Person A wants to know how to make a good looking chair that's medieval-styled. Person B then builds a chair how it's described, and posts pictures of it.
So that's pretty much it. You don't have to answer questions, you can just post certain designs that really aren't big enough for a full gallery topic.