At the end of the film, when the people in the diner count down the final seconds to New Year's, the clock on the wall shows 11:54.
Towards the end of the movie, in the last scene after Amber has dinner with her friends at Rudy's Diner, she stands up to clear the dishes. As she's walking away you can see her wearing brown boots. A few minutes later during the New Year's countdown she's wearing red sneakers, also seen when she goes out to greet the prince outside the diner.
In the opening scene, Amber is given her writing assignment on the Royal family/Prince Richard. When she and her colleagues are researching Prince Richard online, a photo of Lady Sophia dressed in a future movie scene is shown. See the headline, 'SCANDAL IN ALDOVIA! PRINCE'S LONGTIME LOVER SPURNED'. The photo of Sophia in a red dress with diamond necklace, is from the prince's coronation ball, towards the end of the movie.
During the coronation scene, the members of the King's Royal Council seated in the section behind Prince Richard keep changing. The two men at the end of the first row appear and disappear, as does the woman at the end of the second row. A woman in the third row is sometimes at the end with no one visible beside her, and sometimes in the middle with two men to her left and two to her right.
In the first piano scene, Amber's sweater sleeves alternate at different lengths based on camera angle.
When the King died, his son would have become the new king upon death unless he renounced the throne. Coronation is only a formality and is not a requirement for ascending to the throne. Power passes immediately.
The queen is continually referred to by the title 'Majesty' when she is not the Monarch. The title should be strictly for her late husband (or her son).
The bluebird seen when Amber goes horse riding in the snow is a North American species, the Eastern Bluebird. This species would be extremely unlikely to occur on continental Europe.
When the Prince,Emily and Amber are snowball fighting the first time a a carriage with the driver and his two passengers observe the fight. Richard, Amber and Emily return to the castle and are met by the queen she says a groundskeeper saw them in the snow not the carriage driver, unless he is also the groundskeeper.
At 54:10, when Prince Richard and Lady Sophia are in the music room, a green "skrim" can be seen leaning up against the statue post in the background. This is a piece of lighting equipment.
In the opening sequence, views of New York are shown but the last shots shows Chicago with Chicago flags flying.