Fluttershy: It's really amazing... This is our first campaign, and now you're a Princess!
Twilight Sparkle: I'm sure we can do something special for you too.
Fluttershy: You know what's funny? Before, I wouldn't have imagined we could do things like this... But now, maybe Fluttershy CAN do big things too...!
DM: Celestia descends from the night sky, beaming with pride.
Princess Celestia: Allow me to extend my most heartfelt congratulations... *Princess* Twilight Sparkle!
Twilight Sparkle: Wait, how are you here? Aren't we still in a random Ponyville? Wasn't getting here a matter of luck?
DM: She was JUST with you and she followed your light. By that logic, how are YOU here?
Pinkie Pie: Now you've done it! "Why are we here? What is real?"
@ the author note -- I think there's a couple other silly versions of that song linked that are equally worth sharing; specifically, one with the G-Man from Half-Life in Byrne's role, and the one from Muppets Tonight where Kermit's in the oversized suit.
I do agree with the GM's counterpoints to Twilight's question (and chuckle with Pinkie's existential questions), but It's easy to explain -- like the GM said, Celestia followed Twilight; Twilight ended up in the right alternate Ponyville because of the strands of friendship and comradery between her and the rest of the group.
To be honest, I'm a little disappointed that isn't a jacksepticeye joke. His live tour was hilarious and I wish I'd been able to buy more than one show.
Other loaded questions they could ask include "What do you get when you multiply six by nine?", "Who are you?" and "What do you want?". But as those are very loaded, this works out just fine.