It's a 24-hour event, eight creators, they have two pairs of exclusive (never to be sold again) shoes out at their stores.

This is from the inworld notecard. Obviously the landmarks didn't paste, but the stores are listed:
Welcome to our second 21 Shoe Event, the...

Hmmmmmmmmmmm... Me thinks I must do some shoppin'.

Oh and the two pairs are for the price of one. In most cases they're the same shoes in two colors, but I saw at least one that had two different pairs.