I was going to try to write a whole series on Frozen, a la my posts on Sneakers; but after listening to the Scriptnotes podcast interview with the screenwriter Jennifer Lee, I'm not all that sure it's worthwhile. I mean, they have such a good discussion and talk about most of the things I would want to talk about.
It's also interesting to hear the background/production issues and see how that affects the writing and making of the movie. For instance, I read the script, and I noticed that there's a lot of things that are not really explained or described. So the first scene, of the ice harvesters, describes them simply as "dressed in traditional Sami clothing." What does that mean? Well, if you were writing a spec script, you might have to say more to help the reader picture it. But this script gets away with being less descriptive because most of these elements already have art work. So when we first meet Elsa and Anna, they have no description other than their age--but these characters are probably already drawn up and these drawings are available to anyone who needs to know what they look like (casting directors, voice directors, actual animators, etc.).
That said, it's also worth noting (as they do in the podcast) how this script and this movie doesn't spend a lot of time lingering over things; it's always moving forward in some way. So, the ice harvesters sing about how dangerous ice and cold are AND we get introduced to the solitary group of Kristoff and Sven; then we see how Elsa and Anna love to play together AND that Elsa has magical powers AND then we see Elsa hurt Anna with magic. And so on: every scene moves.
Which is why, instead of the sisterly confrontation being at the end, it's in the middle. Which is why, instead of filling in backstory explaining why Elsa is magic, all we get is one line from Papa Troll asking "Born with the powers or cursed?"
(Side note for academics: there's a dozen papers to be written about this movie along some semi-traditional lines: class (do you play with snow like royalty or work with ice like the Saami?); gender (ice is stronger than 100 men according to the song, but it's under the power of one girl); etc.)
In addition to how fast it moves, Frozen would also be a good movie to study for transitions. Some of its transitions are pretty plain--like fading to black and then fading up with the title card "Three Years Later"; but other transitions are a little more organic: the use of the king's narration about the plan for the future blending in with seeing those plans put into action; the fade between a fountain frozen into a threatening ice-form to the threatening mountains that Elsa trudges up; the visiting dignitaries talking about the princess's beauty to a smash-cut of her napping messily; etc.
Following on my recent post about the narrative weight of action scenes, it's also interesting to look at the songs as action scenes. As we'd expect in a musical, many of the songs are primarily useful for telling us about characters. (That is, in many traditional musicals, you break into song when words can no longer do your emotions justice.) So we learn about Olaf's innocence-to-suicide when he sings about summer; and we learn about Anna's excitement and Elsa's dread in "For the First Time in Forever"; and we learn about solitary Kristoff's feelings on society; etc. There's also the pure spectacle of the songs, as when Anna and Hans dance in an entertaining way (their shadows cast on a ship's sails, them doing the robot with mechanical clock figures). There's also a lot of theme work going on in those songs; for instance, in Olaf's song, which is fun (spectacle) and gives us his cracked perspective (a snowman who wants to see summer?), we also get hints of the thematic struggle in the movie between desire and fear.
OK, I have a few more lessons to learn from Frozen, but that's long enough for now.