Checker boxes are wonderful.
By arranging them in various alignments, you can actually create different perceptions of images.
The above is an example of one.
Here, you can see that the supposedly flat surface is made to seem curved out.
There are 2 humps in all, if not more.
This is a simple way where black and white images (in pixels) are produced.
What you will be impressed with is the formation of these checkers to "trick" the eyes and your brain to see things that are just flat surface laid with square / rectangular checkers.
Impressive and amazing, right?