Dolly zoom

Also called the vertigo effect or a zolly. The subject stays the same size in frame while the perspective behind it stretches or compresses, and the reason it unsettles people is that nothing in ordinary vision behaves that way. Hitchcock's Vertigo made it famous and the name stuck. Doing it needs a zoom lens rather than a prime, a smooth camera move, and usually several takes to get the size match right. Video essays and vlogs use it to mark a realisation or a turn in the story. Use it twice in one piece and it stops meaning anything at all.