It's a reference to DeadlyRedCube, a developer friend of Gaslamp He was around during beta and can still be seen once in a while.
Hooray for Easter Eggs I always keep hoping that I will be the first player to spot interesting things the devs leave lying around. Easter Egg hunts are pretty fun.
Yeah, the first time I stumbled into that room, I must have spent most of an hour just trying to interact with that little cube. I cast spells on it, I tried dropping items on it, I clicked spore on it, searched the whole level trying to find something that would trigger it into becoming hostile or turn into an item. It was surprisingly entertaining for just a .png that does nothing. It's awesome.