Android TV is getting Picture-in-Picture, the ability to run two activities on-screen at the same time. This allows you to do things like order a pizza while watching Game of Thrones, or read tweets while watching a football game. It’s a great new feature in Android Nougat.
To help developers understand how to take advantage of these APIs, Google has published an DevByte, a short video explaining a particular topic.
The video covers how to modify your video playing activity to support multi-window and adding a new picture-in-picture button to your playback user interface.
If you want to learn more about picture-in-picture, you can take a look at the Leanback sample app which incorporates these features. Apps can now target Nougat in the Play Store, so you should start seeing apps with this feature. This assumes that you are also on the latest version of Android Nougat.