Google is focusing on the visual experience of Android 12. The latest fruit of that endeavor is a bit of fresh paint on the Discover feed. Google Doodles, the little shifting variations on the Google logo, have appeared at the top of the feed for a while now. But with the latest version of Google search installed on Android 12, Doodles now theme the background of the feed itself. Neat.
The new behavior was spotted by 9to5Google with the latest version of the Google app (22.214.171.124.arm64, on my Pixel 3a XL) running on the Android 12 beta. Today's Doodle is themed after the famous Savoy Ballroom in Harlem, with a sweet little rhythm game featuring some famous jazz and big band performers. On Android 12, it's spreading a sepia background across the Discover feed.
I'm able to see the themed Discover feed both on the Pixel launcher, and in Nova with the Google companion. The theme behavior isn't visible on Android 11, even on Google hardware. That might change at some point — it's possible that Google could bring the functionality to older versions with the Google app. But if this system is relying on the Android 12 theme system, it might stay exclusive to the newer OS.