The word "handsome" isn't often used alongside the word "movie". I'd say it's an attempt by film critics to be creative with language. Of the meanings of the word "handsome", the one that suits this usage case most is:
having pleasing proportions or arrangements, as of shapes or colors; attractive
(Webster's, listed third on TheFreeDictionary page).
Since it really is very unusual to see words "handsome" and "movie" together (although another critic did use this combination in 2004 to describe "The Aviator"), I wouldn't claim to know what it is exactly that the critic means. Probably that the movie is well-cut, with aesthetically pleasing settings etc.
Regarding "anti-Pygmalion", it's a reference to "Pygmalion", a play by George Bernard Shaw (made into a musical(RU) and at some point into a film), in which Professor Higgins works with a working-class girl who cannot speak in a cultured way, improving her pronunciation and grammar. He thus shapes her into a real lady and falls in love with her, the same way that the Greek Pygmalion made a beautiful statue from uncut stone and fell in love with it.
Since Proffessor Higgins improves the way that Eliza Doolittle speaks, apparently, George VI's stammer is about an opposite situation—an individual from the highest class possible who can't speak correctly.