In my opinion, the 1.66:1 framing feels way too tight in many scenes. The crop isn’t even applied consistently, leading me to believe it may not have been intended to be masked.
http://www.framecompare.com/image-compare/screenshotcomparison/9B2BMNNU
Really? Those matted screenshots sure do show more horizontal picture info than the open matte screenshots…
Their point is that the opening title and subsequent crop are different, which would not be the case if the film was intended to be matted to 1.66:1. The 2nd crop has that off center crop reminiscent of how they screwed up Seinfeld and some other shows shot originally for 4:3. The extra image on the left would be matted out when adding the soundtrack to the final print.