BuddyPress allows its members to upload a custom avatar but WordPress doesn’t provides you any option to upload and use a custom avatar directly from your website, instead you have to use Gravatar.Com This is OK because provides you avatar that can be used globally in all WordPress sites simply by using your email address. But some site admins running a multi-user WordPress site face problems because they don’t get any option for uploading avatar image for the users who are not registered on Gravatar.Com