This Bookend looks like a circle or like a square depending on the direction you look at it.
Storage is provided as well for Bookmarks, Pens, Candy etc.

The idea is based on my other Ambiguous Cylinder models, check them out if you like.

If you want both bookends to look the same, just mirror on of them in the Slicer.

If you want both to look differently, just print the part twice.