I've had this wall paper up for quite some time now at least 2 weaks and everyday i look more and more for the cube and i can't find it!!! I'm not sure if this is the place to be asking this question but i thought i might ask anyways, even like a hint would be greatly appreciated. Thanks

In order to make that image from one sphere and one cube I had to duplicate the sphere many many times. You can do this if you put the sphere inside the cube and then make the cube a mirror. So you can't really see the cube, but you can see it's effects.