The cottage is a very modest construction. It appears on the outside as a mere window and door in a wall underneath a small grassy knole. Inside however it's a little different. There are two main rooms. The first of these rooms is a carving area for the Witch where she produces the carvings and small toys she sells.
The second room can only be accessed by the Witch by leaving the cottage, snapping the fingers and then reentering. This room immediately replaces the first when the Witch snaps her fingers; it is a magical laboratory. In the middle of the room is a large black cauldron the Witch uses to brew her spells and potions. It is activated by the Witch clapping her hands. Lining the walls are many shelves, chests and baskets filled with ingredients. When the Witch is away, the cauldron acts as an answering machine, telling people to pour different vials into the cauldron depending on what service they would like.
There has been some speculation as to the true identity of the 'witch', as many fans believe that she actually is the grown version of Boo from Monster's Inc. This has been speculated from the fact that the witch is able to travel to different locations via doors, and that she has a carved Sully in her workshop.