The latest feature to land on YouTube Music introduces is a "Recent activity" carousel that shows the newest additions to your library. At the top of the "Library tab," there is an album artwork carousel that shows what you last listened to. According to 9to5Google, YouTube Music is now A/B testing a broader section to include albums and playlists you've saved to your library. Additions you've made from the new Explore tab will show up in this section after a refresh. Since it's being tested, it's not yet a widely available feature. It's seen as similar to the "Recents" page in Google Play Music, allowing you to browse through your history quickly.