e.g. BMW occasionally sponsors their vehicle to be in a premium film (e.g. Mission Impossible), often doing in-kind marketing agreements. Yet there are many films where BMW vehicles appear with no sponsorship whatsoever because it's logically a good candidate for the car in the situation/conveys the right image. Ford Crown Vics were every film cop car despite Ford's lack of involvement with that. And iPhones appear in a lot of situations where the most likely real-world phone would be an iPhone.

And to dispute a common misnomer, it is entirely within fair use to show brand logos presuming you aren't maligning the product in some way. There is absolutely nothing stopping you from showing a villain with an iPhone presuming you don't pretend the phone is a bomb or something, beyond Apple objecting to giving you free products.

So why do films/shows sometimes occlude the brand? Usually because someone else paid them to show their brand and they don't want brand confusion.

As an aside, elsewhere someone mentioned a show saying "promotional considerations provided by Apple". That specifically means free product, and excludes monetary sponsorship.