Earlier, we saw a panel where Calliope(?)'s ankles were chained - one with Calliope's Caduceus symbol, and one with uu's Ophiuchus symbol.
Now we see Calliope's shackle unlocked but uu's is still locked.
I think the "same body" theory is looking to be more and more a sure bet, though the exact mechanics of it are still a mystery (how do dream selves work, etc).
I'll bet that both Calliope and uu each put a shackle around their body that only they can unlock, as a precaution, to keep them in place.