This type of optical illusion is very popular because it is a real puzzle for the brain. Can you see the cube and its structure clearly?
Our brains tell us that the cube does not act like a cube, because the front and top do not make sense to us. We try to make the image behave as it should, but we cannot. The openings appear to be straightforward enough, but the structure where the points meet appears wrong to us and the shape of the cube changes because of this central point. It is a tricky and effective illusion.
Think you could build that?
Archive of illusions.org: