I think the vertical element was added by Cory. If you click through to the original, the vertical has exactly 2 repeats in the vertical, and something like 2 and 2/3rds repeats horizontally. The image Cory posted has three and an extra pair of wings repeats vertically, and the vertical element occurs at 2 and 2/3rds repeats, and then there's not-quite two more repeats after that horizontally.
It looks like someone did a lazy, slapdash job of creating a bigger tile. The pattern is intricate enough that you don't quite notice...
Although, it does make a decent stereogram source. Can you see the shark?
(Now I just need a depth map of a mass of tentacles.)