It has been reported by people in the business -- quite a few times -- that Apple does not pay for movie or television appearances. At least not directly. Instead they provide hardware for free to be utilized for placements, at least if they're good with the content of the show and format of the placement.
"Apple products do not appear on screen by accident."
If your movie or show is about American upper middle class teens, they're probably going to have iPhones. Apple doesn't need to pay for that to be true, though competitors need to pay for that to not be true.
I mean, tonnes of times you see Apple hardware and the show goes out of its way to occlude that fact (e.g. the MBP with the Apple logo covered). There just happens to be a lot of Apple stuff in the business, and it's what people are comfortable with.