Magic is finicky and hard to control, at best.
So what about portal magic? Possibly the only thing that is weirder than regular magic.
Why was Twi a teen, when she was very clearly in her twenties, or college age.
If the portal can... de-age, for a lack of a better term...

Could it age a certain Pony, up? And keep her well enough for four years? Let her clothing survive? Jeep her hair right?
All this and more.
Enjoy ~

Jay woke up to a world of magic, and other beings. Sadly, he's used to thing. On the bright side, he's used to this.
Maybe he can change this for the better.
Jay ends up during the first movie, after he get's the Nunchaku during Crystalized