https://www.theverge.com/2018/3/7/17088758/android-p-messaging-notifications-iphone-bubble-smart-reply

Google has just announced the Android P developer preview, which is almost exclusively focused on back-end features that primarily concern, you know, developers. Most of the user-facing features won’t be announced until the Google I/O conference in May. But we’re on the lookout for things that look different, and the above screenshot of the Quick Settings panel and notifications drawer definitely drew our eye.

This part of the UI can look wildly different depending on which version of Android you’re using. Google’s panel looks different from Samsung’s or LG’s, for example. But if you’ve been using a Pixel, you can’t help but notice the rounded corners and borders around these UI elements. Right now, in Oreo, these bits are squared off and cover the whole screen.