Originally we were going to have a reading nook and dog area under the stairs.
It would have been with a nice stuffed chair, but this was to give perspective. I envisioned a wall-mounted reading lamp and a small shelf on the wall to hold a drink and a book. This side faces the window and the future door, so it would have been quite nice, I think. And someday, it might actually be used for this purpose. But for now, it's Eddie's computer nook. There is some small amount of trim to finish, so it's still not painted.
And this was for a while the dog's bedroom. I'm not sure when we decided to move him out of there, but Thomas has decided to make it his "office." I have no idea how he fits under there! He's even pinned up some fabric on either side and has one of those push lights that you can hang anywhere.