If it’s just you and your son, I would copy the inspiration photo you have where you liked the mirror. Right now the dark wood and dark bedspread are crowding the room. Since you already have the mirrored nightstands, I would go for a glam look. You don’t have to spend a lot of money to get it. I love the idea of a arched headboard and repeating that arch element in a mirror. Paint the walls a soft gray and get a fabric Roman shade for the window. I would also consider getting a chandelier. A low dresser that is white with mirrored elements would work better then having it be all mirrored. Plus it would be easier to clean with a little one! I’d put the mirror opposite the window and then a large canvas or gallery wall over the dresser opposite the bed.

Center the bed on the wall and get bedside tables to fit the space available. Lamps for reading on them. The wall with the chest is not shown but a dresser would have a lower surface for a guest to place items on. If you need a TV in the room, that would be the wall to hang it on so 2 people could see it easily.