Changing group avatars
When a new group is created, the system assigns to it a default avatar. After that, group administrators can change the group’s avatar using the Group profile web part.
Users can delete the avatar, uploada custom one, or select a predefined avatar.
Changing group avatars in the administration interface
Site administrators can change the avatar of any group. To change a group’s avatar, open the Groups application and edit this group on the General tab.