The story goes that Norman Rockwell, seeking authenticity, wanted to rip holes in the soldiers’s shirt. The GI said fine. Rockwell asked to smear mud on his face and hands. Not a problem.
But when the artist asked to rub dirt on his machine gun, the soldier refused: No proper gunner could tolerate that. So Rockwell portrayed the GI as tattered and begrimed, but with his big gray Browning machine gun sleek and clean.