These two pieces of wall art are placed above the bedside tables. Although they have lamps in front of them, I suspect that when you sit in the bed and look to the side, you can see the art just fine. Definitely an unusual placement.
Of course, there is no actual need for a window to cover if you want to hang drapery. Drapery in itself lends an aesthetic value, so feel free to hang it behind your bed regardless of a window. It will work to ground your bed while adding loads of sensual texture.