The Prince dummy at the beginning of the movie that Giselle made of the True Love she dreamed about is implied to be Edward with the way that the scene fades from the doll into Edward's face and how he comes to rescue her. But while Edward looks like the doll with brown hair and blue eyes, so does Robert. It's also worth mentioning that Edward wears red throughout the whole movie, but Robert is dressed in a blue overcoat for the charity ball, similar to the prince dummy.
Giselle's modern makeover in the ball scene was a contrast from the style of dresses she was wearing up until that point, but it also made her look a lot more "normal" and less of a fairytale princess, highlighting her Character Development.
At the same time, it also contrasts her with everyone else at the ball, who are all dressed up and enjoying their fantasies, while she was faced with reality (that she would not get together with Robert).
It's not just the ball, either. Pay attention to Giselle's dresses as the story progresses. They slowly become less and less ornate and "princess-y" foreshadowing her progression from the Andalasian idealism to a more realistic view of the world.
As someone has perfectly written in the WMG page, Giselle is meant to directly symbolize the evolution of the Disney Princesses. At the beginning, she is a true-love obsessed girly girl (i.e. Snow White, Aurora). After she goes to New York for a little while, like about the time she gets the blue dress, she is still very in the clouds but is SLIGHTLY less naive (i.e. Ariel). Later on, though still bright and romantic, she has a bit more of a spirit and can actually get emotions like anger (i.e. Belle, Jasmine). Then at the climax, she takes action and actually engages in combat (i.e. Pocahontas, Mulan). Finally, at the end, she is a very creative, hard working business woman (i.e. Rapunzel, Tiana).
Her voice gets a lot more mannered and less "Disney Princess"-ish the longer she stays in reality.
This doesn't have anything to do with the film's internal logic, but the musical numbers get more modern as the film progresses. "I've Been Dreaming of a True Love's Kiss" is a bland song reminiscent of Disney's early films, "Happy Working Song" is a jaunty parody, "That's How You Know" is a big bombastic Menken/Ashman-style musical number, and "So Close" is a slow Award-Bait Song, and finally a totally contemporary closing number with guitars and everything. It kind of reflects Giselle's gradual adjustment to the "real world".
Director Kevin Lima said that reflection was intentional.
Like many clocks, the clock at the ball is actually designed to finish its chimes at the "stroke of midnight" instead of start them. Why would anyone want to make a clock like that? Well, remember the guests' comments about "last year's show"? Apparently there's some kind of skit at the ball every year. Perhaps the one that was planned for that year's ball (pre-empted by the real-life drama going on) was fairy-tale themed and featured a When the Clock Strikes Twelve climax.
During the Central Park scene, Robert says that you have take time to get to know a person before getting into a serious relationship, and that many relationships (especially impulsive ones) end unhappily. Giselle insists that you should be romantic and then launches into "That's How You Know". It seems at first that they are presenting completely opposite viewpoints... until you realize that both characters are stressing that relationships only work if you put in the effort. And for a relationship to be happy and successful you need work both to build a strong foundation and to always let the other person know how much they mean to you.
It's hinted that Giselle and Edward have a sort of magical influence on the real world; most obvious is when Giselle gets various street musicians and performers to join her in performing "That's How You Know", but a subtler example is when Edward talks to the TV and it tells him exactly what he needs to know, just as he's asking for it. At first you think it's a coincidence, but then you realize it worked out almost too perfectly. It works in reverse too; the real world has a sort of sobering effect on Giselle, but not on Edward, possibly because he hasn't spent as much time there as she has and because he's not socializing with others as much as she was.
Earlier in the film, Morgan asks Giselle if she's a princess, to which she responds with "not yet". Morgan symbolizes how little girls think. They assume women in beautiful dresses are supposed to be princesses.
Nancy implies that Robert is never romantic or not openly so. She's immediately taken by how openly Edward refers to Giselle as his true love. Nancy and Edward end up together because Edward represents everything she wants in romance.
Nancy and Edward randomly and hurriedly get together. It fits in with Edward, who's still very much a fairy tale character. And fairy tale characters fall in love at first sight. Nancy just happened to be romantic enough to go along with it. Now that Giselle's more modern, relationships take her slightly longer to develop- but as she is actually a fairy tale nearly-princess, it still doesn't really take more than a few days to acquire a true love. Yes, fairy tales and Disney movies really do come true.
Also, Nancy and Edward represent the happy ending that the film has to have to be a good Disney fairy tale- pair the spares is the way to ensure that all good characters magically have a happy ending, and in a movie like this, naturally it would happen in a blatant, unexplainable way.
In "That's How You Know", Giselle mentions "Because he'll wear your favourite color/just so he can match your eyes". While Edward wears red, Robert wears blue, which is the color of Giselle's eyes.
There's a blink-and-you-miss-it bit of Giselle reading the book on heroic women that Robert gave Morgan. Fast forward to the climax and she tosses the "Damsel in Distress" mindset out the window and sets off to save Robert from Narissa. Easy to imagine that that book taught her that women could be heroes too instead of always being helpless, inspiring her to step up and rescue her True Love.
Giselle claims in her "True Love's Kiss" song that "the lips are the only parts that touch". How sad. Because of her living alone all those years in that abandoned cottage, the poor girl has never heard of hugging. This could also be an in-joke about how the kisses in Disney animation are always "chaste kisses", i. e., the kissing characters never touch their tongues, only lips.
What about the soup from which the Queen is calling Nathaniel? Remember the poisoned apples? Yes.
Just how big of a bill did Giselle run up on Robert's credit card? Not too disturbing since lawyers like Robert probably rack up high billable hours, so is fairly well off, but he's going to have an unpleasant surprise at month's end.
Well Giselle's fashion designer business seems to be booming so she'll easily be able to pay him back.
In the epilogue we see Robert helping Giselle out in her studio, during what is obviously office hours. It is safe to assume that it is Giselle and her Andalasia Fashions that earns the majority of the bread on the table now instead of Robert's lawyer job just like another Disney princess. Robert giving up his old job itself is a good testament of how well Giselle is paid in her job alone.
In the fashion industry, Giselle makes both a good fashion designer and a supermodel. No wonder she is so well paid.
Being Trapped in Another World, Giselle wandered throughout the streets of New York upon her arrival. At night. We already saw her mugged, but she could have suffered much worse. She was also shown leaving the subway in the Bowery, a rather seedy neighborhood at night.
Just from the homeless man's appearance, he probably snatched her tiara with the intent of pawning it off for drug money.
