It is sddm
sddm is the default display manager that shows up when you first log
in to Lubuntu or logout or choose to another session. There is no
graphical application to do this currently.
Lubuntu 20.04 uses xscreensaver to provide screen locking.
But the lock screen that comes up after pressing Ctrl+Alt+Del is very poor in aesthetics.
(On my Lubuntu 20.04, Ctrl+Alt+Del launches the task manager.)
Anyway, the screen in question looks probably like this:
I'm assuming "very poor in aesthetics" refers to the "flaming computer" image on the ...
The ubuntu documentation gives instructions on how to install lubuntu minimal.
This is completely unrelated to the Live USB persistence. The instructions on that page are for installing ubuntu from mini.iso. This mini.iso contains only installer and not Live (Try Ubuntu) option. Hence it is not possible to run minimal lubuntu.
Adding Persistence to a ...
The host os and host device formatting can cause this issue. My host os is Mac OS, I have mounted shared folders which are APFS and exFat.
sudo mount -o defaults,uid=1000,gid=$(getent group docker | cut -d: -f3) -t vboxsf mcs /media/sf_mcs
sudo mount -o defaults,uid=1000,gid=$(getent group docker | cut -d: -f3) -t vboxsf active /media/sf_active
tar cvf ...