Norway - they have to list positive traits about him in order to make his being "told off" by Granny more humiliating.
It's basically "here's several reasons he's an adult, and he's gonna be king, but by God he still gets in trouble when he misbehaves in public".
I thought the interaction was adorable, and not at all him being "told off", but perhaps him being reminded what he was there for. In many ways he's not there for the fly over himself, but to be seen by the crowds, and him crouching down to point things out to George (while adorable in itself, and a great moment to see), it means that the people down in the street can't see William - he's too low.
Thinking about it, it actually kind of makes me feel bad for William - this is a very literal depiction of his struggle between balancing being a good parent and being a good Royal.
It seemed to me she was more concerned with William standing up than if George was ok. Not the end of the world but very telling IMO