When it comes to wallpapers, you could do a similar trick on X11 DEs by putting it onto the root window (with a tool like xwinwrap) and on Wayland DEs that support layer-shell (with a tool like windowtolayer). I'm not aware of screen lockers that do something like that, but you could always write your own one.
When it comes to wallpapers, you could do a similar trick on X11 DEs by putting it onto the root window (with a tool like xwinwrap) and on Wayland DEs that support layer-shell (with a tool like windowtolayer). I'm not aware of screen lockers that do something like that, but you could always write your own one.