Hi Jonathan,
There is a known issue about the avatars in notifications and we have addressed this internally.
I have helped you apply the fixes in the following files:
JoomlaFolder/administrator/components/com_easysocial/includes/template/helpers/avatar.php
JoomlaFolder/components/com_easysocial/themes/wireframe/helpers/avatar/user.php
Can you help us check the system notifications again? Thanks.