Jason: Do you ever wonder if somewhere out there's a parallel universe with people exactly like us? They might even right now be having this exact conversation. Paige: I think we'd hear the screaming. Jason: I'm sorry. Were you napping?
The joke here is that Paige is screaming, so in an alternate universe, they’d hear Paige. But Paige isn’t screaming. This comic has never made sense to me.
But if it was an alt universe, and Paige was screaming, wouldn’t she have been screaming right now? This specific strip has always not made sense to me
Parallel universes don’t necessary mean the exact same thing is happening in an infinite number of universes scattered around space. They just mean every single possible thing that could happen at that scenario might be happening in an alternate universe.