Architect Rafael Viñoly and his team prepared for months to pitch what they hoped would be the winning design concept for the National Medal of Honor Museum, in Arlington. They had extensive drawings, a digital rendering, and a physical scale model, but Viñoly began the meeting with a single visual: a raw slab of steel.“When he first unveiled it, everyone just stared, and you could tell they were thinking, ‘What is this?’ ” says Bassam Komati, a partner at Rafael Viñoly Architects. “But then Rafael picked it up and passed the steel to the person next to him. As it made its way around the conference table, people commented on the weight, and Rafael said, ‘That’s the museum—the only way to really understand it is to…