Round the user picture on lock dialog.

All user dialogs (Linux, Windows, Mac, Android, etc..), or any
representation of a user as an avatar in the web are round

Also, it shows an emblem icon to note that it is logged in as
in other dialogs.

Both options can be made configurable by the user very easily,
but at least (IMHO of course), I think it respects the
preference of the majority of users.
2 jobs for !13 with round in 2 minutes and 12 seconds (queued for 7 seconds)
latest detached
Status Name Job ID Coverage
passed build #19249


passed distcheck #19250