I'd consider painting the walls a different color that you like. Start with desk placement. I'd try the desk on the wall to the left of the window, so you can look out the window or look to your right to see people entering the room.

I’d leave the desk on the wall it’s on but centered and pulled off the wall quite a bit. Chair behind it. Add some art :)

Big desk, storage credenza, colorful art of your choosing, fun paint, lose the door hanging.