This new option is only available in private albums, not those you’ve shared.
Google Photos is one of the best ways to manage your ever-expanding photos. Although the big G has made constant improvements to the photo organization service, it has its share of misunderstandings. One of them is the impossibility to directly trash the photos of an album from the Android application. This feature has been available on the web for years, but was missing from the mobile app for some reason.
Google has quietly fixed this anomaly in the Google Photos Android app. There is now an option to directly trash photos from an album in the Android app, but it is only available for private albums. In shared albums, you’ll always need to start by deleting photos from the album, finding them in the library, and then deleting them from there. This limitation does not exist on the web, where you can directly move photos to the trash from a shared album.
What’s odd is that the ability to move photos directly to the trash in shared albums has also been present in the iOS version of the app for quite some time. So it’s unclear why Google didn’t add this feature for shared albums and why it took so long to add the button for private albums on Android in the first place. It’s an annoying issue with the service that makes managing albums shared from mobile a bit more difficult than it should be.