https://thenextweb.com/google/2019/03/18/android-qs-hidden-bubbles-suggest-google-is-rethinking-notifications/

Despite multiple redesigns and fundamental changes, one thing has remained true since the very first Android phone: you swipe down from the top to access your notifications. But Android Q Beta 1 shows Google is at least considering an alternative.

As first reported by 9to5Google, Android Q includes a hidden feature that duplicates your notifications in a small floating ‘bubble.’ If you use Facebook Messenger on Android, you might know what I mean. Facebook calls the feature “chat heads” but it’s essentially the same concept: an always-on-top bubble that you can move around your screen and use to quickly access conversations without leaving your existing app. The Phone app on Pixel devices behaves similarly.