What makes this all the more galling is that Apple didn’t use to do this! Back in iOS 10, videos in the TV app - even the new TV app rolled out with iOS 10.2 in December 2016 - would default to landscape mode, because of course they would.
There is also no way to lock it in landscape mode once rotated, so better make sure to hold that phone steady. The only way is to disable rotation lock, which requires swiping down into the control center (since there’s no way to access it directly on the playback screen), and then rotate the device. If your device is set in rotation lock - as most iPhones tend to be in my experience - there is no way to watch video in landscape. Here’s how it works: if you’re watching a video on the TV app - presumably, one that you bought or rented on iTunes, streamed through one of Apple’s native partner channels, like HBO or Showtime, or whatever the method for using Apple TV Plus will be - on an iOS device, it will play in portrait. There’s simply no way around it - actually watching video using Apple’s native TV app is just an appalling user experience. So why does it still default to portrait mode for playing back video?
Apple just released its updated Apple TV app today across iOS and tvOS - it’s a big deal for the company, laying the crucial groundwork for the company’s new TV strategy with direct-to-consumer subscriptions and Apple’s own upcoming Apple TV Plus video streaming service.
