The Mutt email client which is installed by default on Freedombone now supports the X-Face email header. This is a very old standard for email avatars from the 1980s. It's a blatantly geeky, almost easter egg, type of feature. Supporting standards like this is fun because they're so anachronistic that they are able to fly under the radar of the modern internet. Hence you could possibly exchange subversive ultra low resolution avatar iconography without that being especially obvious even when emails are entirely sent in the clear.
If you ssh into your Freedombone server then there is now an option on the control panel to add an avatar image, and this can either be an image file or a URL. It will then get converted to a binary 48x48 image and attached to any email sent from the Mutt client. You may need to experiment by sending emails to yourself to obtain an avatar which looks at all intelligible. Obviously at such a low resolution any details get lost.
If you see an X-Face header in the Mutt email client you can then press Escape and then the f key to show it .
I did think of also adding this to webmail and the members screen of the web interface, but I don't think that would be a good idea. Since Freedombone is primarily aimed at more mainstream uses the typical expectations around the image quality of avatars will be vastly higher than X-Face can provide, and would merely be a source of frustration.
There was very little digital photography or scanning in the 1980s (fax machines would be about as close as it got) and so in the time frame when X-Face was invented people were probably making hand-drawn avatars using a bitmap editor, or even just on graph paper and then doing the calculations to convert to bytes manually. You could get imaginative and draw a 48x48 grid on acetate and then overlay that onto a chemical photograph of your face to obtain a crude digitization. Especially considering the tight bandwidth constraints and high telecoms costs in the 1980s, adding avatars would have been an extremely luxurious feature.