Josh Centers, TidBITS:

tvOS 13 is here, but the update is sufficiently subtle that you may not even realize you’re running it, unless you’ve bumped into the new auto-play videos on the Home screen or one of the bugs that our readers have been reporting. I covered most of what’s new earlier this year in “An Early Look at tvOS 13” (10 June 2019), but an interesting new feature cropped up later in the beta cycle: Picture in Picture (PiP).

And:

Likely for the sake of simplicity, in the shipping version of tvOS 13, any video playing in PiP disappears if you return to the Home screen.

Nice explainer. Hoping Apple continues to develop PiP. It’s especially useful for live TV, where you keep an eye on the boxed video, bring it to the forefront when something significant happens.