Those who are watching TV shows can exit the app by swiping up from the bottom, and their iPhone or iPad will go back to the home screen. The video will continue to play PIP (picture in picture), though. Once the window is on the screen, it can be changed in size and moved around the screen.
This feature is available to all YouTube Premium subscribers who want to keep watching videos while doing other things or just listen to audio when the device is locked. It works on both Android and iOS.
Google has said that it plans to make a picture-in-picture mode for all YouTube users in the US. This hasn’t been done yet.