I would paint the walls behind the shelf a navy or dark blue to make the copper piping pop. Add plywood paneling to the bottom to act as your headboard. You don't really need one, just use a regular bed frame. Maybe add a long bolster pillow at the top to cushion your head. Paint the ceiling white with a matte paint, it looks shiny. Get long curtains to the floor in a blue pattern. Add a hanging list fixture, maybe rattan or something to add in wooden detailing.
The ikea bedframe is also not a good color for the room too dark. You need to add lighter wood detailing not black.
Good luck!
Q