Comment # 4 on bug 1001364 from Fabian Vogt

(In reply to Cor Blom from comment #3)
> I hope reopening this bug is the right procedure here.
> 
> Since the last update I have lost the photos of users in the sddm screen and
> the lockscreen. This is a pc with four users and each has a photo as avatar,
> which worked perfectly until the last update to 5.8 final.
> 
> I now see the user-identity icon.
> 
> I assume this patch that this bug report speaks about is the culprit.
> 
> The photos were saved as .face and .face.icon linked to the former in the
> user's home directory and added a long time ago. I think in kde 4 times and
> I think somewhere in systemsettings then. (I have a separate home partition
> and even if I reformat /home, or want to test a setup, I use the data from a
> backup).

Indeed, I broke it. Sorry!
The patch was a bit too overzealous at blocking face icons, I thought they were
saved as <username>.face.icon everywhere.
As a workaround, you can copy your .face.icon to
/usr/share/sddm/faces/<username>.face.icon.