Calling it now
Pauline's a kid because they couldn't get her to work as an adult
I'm seriously
Adult Pauline was too big to ride on Donkey Kong without being intrusive to the player's experience or it wasn't working for the game mechanics they were attempting so they had to come up with a way to shrink her down
This is Odyssey team we're talking about
Before the Broodals were even rabbits they still nailed how exactly their boss fights would go
Form meets function, that's how they design games