With Clusters enabled, Avatars come to life by giving you an intuitive way of navigating every email from that sender. There is no need to search for a single sender anymore.
There are three types of Clusters: People, Group, and Services.
People: Tapping on this Avatar will show you every message from that specific person, in one convenient screen.
Services: Services are for all of those newsletters, coupons, or updates that, while important, can quickly leave your inbox looking like a mess. – P.S. This makes deleting a bunch of spam a breeze.