A video went up on Google Photos' Youtube today that introduced the shared albums feature, allowing you to easily upload all your phone pics and put them in front of the eyes of friends & family. A handy feature for those who don't really want to share everything on Facebook, or bother playing around with Facebook groups.
Seeing as its main competitor, Apple Photos, is exclusive to Apple products, this puts Google Photos in quite a strategic place, being available on iOS, Android, and Windows Phones. Album owners can also move photos around after the upload, allowing for greater organisation and control.
It still lacks social features such as "likes", comments, and so on. It doesn't look like it's actually aiming to be a social network, but a writer at The Verge has been using it for a week and found the missing features very noticeable, saying the service felt hollow.
At the moment it seems like the Albums are meant to be exactly that: A folder of photos based around a specific event or time, as opposed to an endless stream of content. The chronological sorting, and future comments feature that will apply to the album but not individual photos all point to this.
iOS users will notice it kind of makes it look like your images are moving while you're in the folder though, which is a cool feature that will make its way onto the other platforms later on.