Screen Reactions on Android 17 QPR1 Beta 4

What are "Screen Reactions"? Patrick Shehane, Engineering Director at Google explains:
We’re making it easier to create reaction videos without the hassle of switching apps or setting up a green screen. With Screen Reactions, in just a few taps you can record yourself and your screen at the same time, letting you overlay your authentic response directly onto trending clips, wild comment sections or your latest gift guide. You’ll see this feature roll out first on Pixel devices this summer.
Google has enabled the Screen Reactions feature in the latest Android 17 QPR1 Beta 4. Besides creating content, I can imagine myself using it to record walkthroughs when asked for how-to instructions from family and friends.