The Key To Reserva is apparently a script written by Alfred Hitchcock, which never made it to the big screen. It actually seems to be just the beginning of a script, as it's only four pages long, and one of the pages is missing. Martin Scorcese decided to shoot the scenes, as a tribute to Hitchcock, for Freixenet sparkling wines, who make one kick-ass commercial a year, featuring a big star.
What I don't get is why this thing is getting such rave reviews everywhere I read about it. I agree that it's shot beautifully, and it does feel a bit like a Hitchcock flick. But after that, I was left with a "yeh, whatever" kind of feeling. I might be the ridiculous product placement, or the fact that I remember Freixenet from college as being a really bad champagne, or that I'm biased against anything that comes out of a certain ad agency. But even after all that, there's still "yeh, whatever".
Finally, at one point Scorcese makes the claim that a director making another director's unfinished work has never been done before. Isn't that what AI was, with Speiberg stepping in for Stanley Kubrick? Oh well, who pays attention to the details?