This is a fairy ticket window right below the actual ticket window at The Ark There are actual tickets inside and if you look around the corner, you can see the entrance to the ticket box.
Head inside Sweetwaters Cafe and you will find a fairy door with their own miniture coffee house. Adorable!
This door was outside Peaceable Kingdom. If you go inside you can see a scene from the fairy's own store but they were closed so we'll have to do it another time.