It's not very clear what is supposed to be mysterious about it, seems like its just a traditional design. Admittedly the origin is somewhat unclear, but I'm gue

It's not very clear what is supposed to be mysterious about it, seems like its just a traditional design. Admittedly the origin is somewhat unclear, but I'm guessing its that more mundane sort of mystery where you don't know something because it was done long ago and you don't know who has a copy of the receipt.