Clearly Disney focuses on the snow queen character, trying to explain us where she comes from, why she became the snow queen, who she is, creating a whole fascinating background : Elsa, her royal family, her secret, her destiny, her sister, her exile, and how she became cold and stark...
I guess Disney scenarists have been stuck for a very long time because of the two children friends theme, and the male figure (kay) being trapped and inactive during the whole story.
So they decide to make the girl and the boy meet DURING the travel.
They change the "girl saves boy" quest for something more ambitious and original : the girl wants to save the whole kingdom from destruction now, and the snow queen herself, because it's her sister. Here are all the new symbols, plus the emotional sister stuff, the accepting who you are theme, and the power of love bringing you back to your family, etc... Those themes are enough. We won't have the God and Angels themes, too abstract. But i still hope we will have some roses, somes gipsies or even that blasted mirror, maybe in Elsa's palace (like a Ursula crystal ball or Beast window open to the outside world ?)
