As you can see, when unlocking from sleep there is an, in my opinion, intrusive white box surrounding icon and password. Is it possible to remove it?
It is not a white overlay, but a real UI element (likely a window without title bar) containing the password box and your avatar. You can click on it without dismissing the password box contents, but if you click outside, they are removed. You can observe similar behavior with a direct
There is no preference for it. Since it's not just a pretty image like the circle around the avatar, it is not easily editable.