They count from 0 to 15, down the left side then rotated 180° and up the right side. 0s are white, 1s are black, I think they look like fish in seaweed. You can see two black fish, or two white fish. Thus Pisces. Which is twoness. Which is binary.
I think the symmetry is very pleasing as well. The numbers 0-7 fit right into 8-15 if you fold them over.
Yep I can see the theme of binary and symmetry. What I meant to ask was if the binary numbers you used mean something mathematically or otherwise apart from creating the pattern you needed. Reading from left to right the numbers are: Binary DEC HEX 00001111 15 F 00010111 23 17 00101011 43 2B 00110011 51 33 01001101 77 4D 01010101 85 55 01101001 105 69 01110001 113 71 I didn't see an immediate pattern in the numbers, they are not primes or anything. It's a pretty interesting picture as you mention you can fold it along its Y axis and the 0 and 1's match up. This is also true along the X axis. Its a simple idea but quite pleasing.