Hubzilla Tips and Tricks
The EFF Privacy Badger plugin breaks the profile images on the directory page (and perhaps elsewhere). It will also break the nomadic authentication. See this link for details.
Instead of the same avatar, assign new users who haven't uploaded a profile picture a randomly selected Creative Tail animal icon. There are roughly 40 avatars available from this set, Creative Commons licensed for commercial use. There's an add-on called Cavatar in dev that implments this.