I may have mentioned this before and I’m sure many other folks have. And it’s probably just because its a basic shape and not actually indicative of anything, but I’ve always found it interesting that the doorways of the Sky Arena are hexagonal

considering

I could easily see Kindergarten Gems having to fight in gladiatorial battles to weed out the weak and find out which ones were the strongest and most successful (and thus most useful). This would also make “Tiger Millionaire” a bit of foreshadowing and also serve as further explanation as to why Garnet and Pearl were so against Amethyst wrestling (aside from it being unethical for a Gem to be fighting humans)