So I have an Apple TV 4, not the 4K model. And I just got an iPhone X. And I have a new Sony 4K TV. So I took some test video on my iPhone X in 4K and then used AirPlay to send it to my new Sony 4K TV. Realizing that my ATV4 is not 4K compatible, I was expecting a mediocre picture. Wow was I wrong. It's the clearest, sharpest iPhone video I've ever shot, took it in a grocery store, hundreds of products, hundreds of packages, the typography is clear as crystal, it's definitely looks like a 4K video being pushed to my 4K TV. But is that possible? Does the non-4K ATV4 allow pass-thru 4K via AirPlay? Or are my eyes deceiving me and what I'm really seeing is 1080p. But why then does it look so good?