I added a battery operated light in the top. It has dolls, bears, dollhouses, and a host of miscellaneous toys.
The little theatre on the top shelf was a printie that has held up immensely well. When I started doing 1/12 scale (which this is) I used to put a Hershey bar in each scene. There it is in the wagon.
The battery operated light is in the little jewelry box that is attached to the top where you just pull off the lid to turn on the light. I really like lighted projects, but don't always do it.
I hope inspiration comes to you for your favorite themes.