Mr. Musk is fundamentally a creature of Silicon Valley, a scene that initiated an entire revolution in power dressing. The young masters of that universe dressed down to show that they were members of a new elite — one that refused to dress like the grown-ups they were about to topple. It was the defeat of the suit by the T-shirt.

President Donald Trump on Tuesday appeared to read from a piece of paper detailing Tesla's selling points at the White House. Trump has tapped Elon Musk, the head of Tesla and SpaceX, to oversee the Department of Government Efficiency (DOGE).