Right now in the theme you can't hide the avatar only when it's empty.
It seems like the 'blank' avatar should not show at all, but instead, it will load a blank image the same size as is being passed to the avatar.
If possible, avatars that are not set -- at least when the 'blank' option is picked under WP Admin > Settings > Discussion -- should not display anything, and should not create a 'space' -- instead, they should look like avatars are turned off.
Right now in the theme you can't hide the avatar only when it's empty.
It seems like the 'blank' avatar should not show at all, but instead, it will load a blank image the same size as is being passed to the avatar.
If possible, avatars that are not set -- at least when the 'blank' option is picked under WP Admin > Settings > Discussion -- should not display anything, and should not create a 'space' -- instead, they should look like avatars are turned off.