Steampunk Mechanical Arm Prototype on a Workbench

A steampunk mechanical prosthetic arm lying on a cluttered inventor's workbench, the arm made of polished brass and copper with visible gears and pistons, leather straps and a padded elbow joint, a glass pressure gauge mounted on the forearm, small tools and blueprints scattered around it, a lathe and a vice visible in the background, warm tungsten desk lamp light from the upper left, dust particles in the light beam, no text, no letters Art direction controls: deep cobalt, warm cream, and charcoal, a centered hero composition with deliberate negative space, quiet and editorial.