The Shared Albums feature in Google Photos is getting smarter and more useful in the near future, when the rollout of the app's newest versions will be complete on Android and iOS. In Google Photos 1.10 for iOS and 1.20 for Android, people who join an album can now add comments to photos and even to the album itself. There's still no way to Like or +1 anything, though. Additionally, the service now makes it easier for you to add your own photos to an album someone else has shared with you. That's because you now get smart suggestions for which photos to add to such a shared album -...
Source: http://www.gsmarena.com/shared_albums_in_google_photos_get_comments_smart_suggestions-news-18187.php