If you're a bit like me, your first response will probably something like 'Okay, a shelf, yeah, so?' In that case I suggest that you read the next line and then quickly click on through to the rest of the images.
What you are looking at here is Shellf: a bedside table to hide your little secrets. The designer says this:
Objects take volumes out of the space which surrounds you. Here the idea is to use the space which is taken by the object.