Ed Greshko writes:
Install lightdm-gtk-greeter-settings. I'm surprised it isn't installed by
default.
This one prompted me for my password before it ran (and caused an SELinux
alert that's yet to be fixed, but that's off-topic).
Afterwards, the "Default user image" option started browsing for a file …in
the root's home directory.
Pointing it to a file in my home directory resulted in a caution icon, with
a tooltip informing me that the file is not accessible. It was fairly
obvious that this option was only to select the image file to be used when
the selected user's profile picture is not set.
In the end, it didn't matter. I attempted to create $HOME/.face myself,
using just the available tools, namely gimp, by cropping and saving my mug
shot. I failed, since gimp was very confused by my attempts to save a jpg-
formatted image as $HOME/.face, going only as far as $HOME/.jpg, so I
relented and renamed it manually. In the end, nothing changed, and the
greeter still showed the default, feature-less profile picture. I even
rebooted, so, who knows what the problem is. Maybe it has to be a .gif.
Maybe it has to be .png. Maybe it is being blocked by SELinux, who knows.