It's worse than you think. As an advertiser, I can actually buy targeted product placements in shows. So, let's say I'm Google, and I know you recently searched for a Google Pixel. If I pay for product placements in the next Prime show, I can get all the phones to be Pixels when you watch it.
But if your friend searched for an iPhone, and he gets targeted by apple, the phones in the show could be iPhones.