A friend was telling me in passing that she joined "the local hash," and I asked her what it was about and she said: "Great! Elevator Pitch! ..." and told very me quickly what it was all about. I didn't have one for WP.
The idea is that in roughly the amount of time it takes in an elevator, you tell a friend or stranger everything about your group in a quick summary. This is not the same as What is Worldbuilding, but rather:
What is our Worldbuilding Elevator Pitch?
How would you describe Worldbuilding.se in 30 seconds or so?