What does it mean that Thomas Keller and his Yountville restaurants starred in a long, poignant, beautifully cinematographic ad for American Express, which dramatically ran three-quarters of the way through the Oscars? Well, a lot of things. For one, he’s just as famous as half the nominees. Also, he’s maybe opening a new place. Lastly, it kind of feels like he just negotiated the best deal in restaurant-advertising history right there. Does it not?