We all remember how in the episode 3 Gems and a Baby, when their all in the van with Steven, they discuss what he might be. And the most interesting one out of all of them was that Steven is a fusion, and that she's trapped inside the human baby like form. And then Pearl reaches down, touches the pink gem, and seems to be doing something to it... but what? Perhaps she was trying to get who ever Rose fused with to lose control, so they would both come out from fusion. If he is a fusion, the biggest question is: who is Rose fused with? Not Greg, not Amethyst, Pearl, or Garnet. But that also begs another question: wouldn't there be another gem on Steven's body? And why is he half-human then? I'm still trying to figure this whole thing out.