A gravatar is an image registered to an e-mail address.
You can submit yours on-line at https://en.gravatar.com/.
The following variables offer control over how things are displayed.
gnus-gravatar-size ¶The size in pixels of gravatars. Gravatars are always square, so one
number for the size is enough. If nil, this defaults to the
value of gravatar-size.
gnus-gravatar-properties ¶List of image properties applied to Gravatar images (see Image Descriptors in The Emacs Lisp Reference Manual).
gnus-gravatar-too-ugly ¶Regexp that matches mail addresses or names of people whose avatars
should not be displayed, or nil to display all avatars. It
defaults to the value of gnus-article-x-face-too-ugly
(see X-Face).
If you want to see gravatars in the From field, set:
(setq gnus-treat-from-gravatar 'head)
If you want to see them in the Cc and To fields, set:
(setq gnus-treat-mail-gravatar 'head)