If Wreck-It Ralph was Disney's Atypical movie in the modern era, than Frozen is an offshoot of Disney's "typical movie", only where Reality Ensues. All the characters and tropes are there to see, but are done in such a way that sets it apart from anything before it in the disney formula. For example...
Love at First Sight: While not played as straight as say Enchanted or The Little Mermaid, our hero, Anna, falls for a handsome prince of a small island nation who incidentally has 12 other siblings (Another first. Whoever heard of a prince with older brothers?) but who seems at first a standard Prince Charming for Anna to fall for, marry and get her Happily Ever After. However, when they bring it before the oldest relation Anna has left (big queen Elsa), she very quickly makes it clear that she will not have her little sister go off marrying someone she just met. Just like how a real parent in our time would behave. Oddly enough though, despite this, it's the only thing they can think of to help Anna in her time of need since they'd been close enough that Anna still believes in the truth. However, it's only in The Reveal that we see the danger such a belief can lead to.
How Do I Shot Web?: The very reason for much of the plot hinges around a decision made around this. All Elsa and her parents wanted was to get her ice powers under control. A lesson in discipline which would normally be perfectly acceptable to work with. However, the lessons in discipline proved futile as the power only continued to grow, and the discipline, shields and practice ultimately lead to a Self-Fulfilling Prophecy. The Trolls warned that snow and ice was beautiful, but that fear would be the problem. Ultimately, that discipline led not to a control that allowed the powers to be used well, but a repression that eventually went out of control and lead to that fear they were trying to prevent.
Plucky Comic Relief: Olaf the snowman is the movie's true comic relief. He also carries with his many Visual Gag and fun jokes a much more serious side that makes him essential to understanding the plot. Olaf was first introduced inanimately, as a snowman created by two sisters having fun. And it was only after Elsa ran away that her recreating him gave him sentience. As this was when she embraced her powers, that gives Olaf a possibly darker meaning to his character: he's the living representation of childlike devotion shared between Elsa and Anna. It is something that surprises both of them to see him alive and moving around. However, that childlike devotion also hammers in perhaps the simplest of answers for the hardest of situations: Love is putting others first, even when you might hurt yourself doing it. Olaf's big scene is him helping Anna survive the cold by building a fire. Even if he'd hurt himself (which he did actually know about surprisingly), that devotion is something that those who love each other would gladly show. And all it took was a simple snowman to bring that to light for our heroine.
Prince Charming: While subverting this trope is nothing new, and the Lovable Rogue has replaced it as the popular male character type, Frozen decides to show the dangers of someone who can easily fake being the Adorkable Prince just trying to help and the danger of readily trusting people you just met.
Conveniently an Orphan: This movie does NOT make light the loss of a parent. While other movies might talk about its impact on the characters, and a Missing Mom and Disappeared Dad are nothing new in Disney, this movie hits the hardest by having the loss of BOTH parents at the same time. While their deaths aren't always referenced, their disappearance was like a final blow to the hope for love for Elsa who had literally nobody else to talk to about her power. Perhaps as Elsa got older, her parents might have found other ways to encourage her power growth, but as it was, they both died leaving two very devastated daughters who would one day have to come to terms with the secret that was hidden between them.
The High Queen / God Save Us from the Queen!: Funny enough, this distinction is perhaps a real first for Disney: creating a movie based around a queen who's not intentionally evil and given a LOT more screentime to develop the idea. Initially, out of respect and possibly curiosity, The Kingdom embraces the coming of the queen, seeing it as a chance to get to know her better, finally have the bloodline come out in public again. And while shocked by their queen's other talent, it's the leadership who first starts calling out for blood when the snow doesn't stop. In some ways, it's a realistic look at how such a power might color the way leadership looks at a queen and how a queen might become a target for subterfuge. And, once that power is finally brought under control, it can safely return from one extreme to the other.
True Love's Kiss: A major first for Disney's formula, the one that started back in Snow White, that is played at, hinted at, built up to, changed around, and ultimately NOT played out as a crucial element in the plot resolution of the movie. Because Grand Pabbie was vague about the "act" of true love, it is assumed to be a True Love's Kiss. After Hans shows his true colors, Anna realizes that her true love is really Kristoff. However, seeing her sister in danger, she sacrifices her life to save Elsa just as the curse takes full effect and Anna freezes to death. Whether it is Anna's love for her Elsa and her sacrifice (or both) that does it, or Elsa's love for Anna and her sorrow at the death of the only person she had left in the world, it is an act of True Love. It is not love between a man and a woman that saves the day, but of familial love and sisterly love. This act of love can be seen as just as strong, if not stronger.
Elsa's dress style and ideas of sexuality
As the queen of her parent's kingdom, Elsa is very covered up and feels confined due to her role and powers. Once she runs away and creates her own ice palace out in the wilderness, her outfit changes according. As the Snow Queen, she is much less covered up and declares that she is free of social expectations.
The imagery calls upon the idea of the sexually liberated woman to add to the notion that she's casting away all manner of shame (contributing to some interpretations that the ice powers are a metaphor for homosexuality).
The choice has been criticized by stating that, in order to be free, you also need to "get hot", as if girls need to wrestle with the beauty myth even more. Whether this is the case or not is up for interpretation.
It contributes to the idea that, the more sexual and sexually active you are, the more comfortable you are with yourself. This is dismissive of people like asexuals or those who are otherwise not interested in sex.