Optical Illusion Pen Holder

This pen holder is a fun item for your desk. We are fairly sure it was made in Italy.

There are a number of holes in the top, which allow you to pop quite a few pens or pencils in, to keep them tidy. However when you look inside the box, they are not there! They do appear at the bottom though. It is just the middle section where they are missing.

This optical illusion is created using mirrors. Can you see how it works?