>>527936403
Introducing her as a young Pauline IS the mystery, it's an unspoken mystery solely by the fact that we know Pauline isn't usually a kid, so the obvious answer is that she was aged down or time displaced or something.
I'm just gonna say it, the idea that this is somehow a reboot/prequel is actually ridiculous, there's no actual proof for any of that, and people are only assuming it because they saw young Pauline and didn't think about it for more than 1 second.