Etsy offers quite a few different ways for buyers to search for items, and for sellers to show their items. One of these is the list of "Treasuries," each built around a specific theme, which displays items from different sellers. It's nice to make Treasuries of fellow Etsians' work, but it's more fun to be listed in someone else's Treasury! Either way it increases traffic to your shop, and gets your brand noticed, which hopefully leads to sales.
There's a lot of talent on Etsy, and the Interior Design Team can claim many artisans. Here's a screenshot of the team treasury I posted today.