Most Disney fans remember two key details from Frozen: Elsa's power ballad "Let It Go," and the icy blue dress she wears while singing it. Nearly six years after the film's 2013 release, the "Elsa costume" is still one of the top-selling Halloween costumes at stores like Walmart. Her look may be popular, but according to a fashion historian, Elsa's signature outfit isn't necessarily true to what real women wore at the time.

In the latest installment of Glamour's "Fashion Experts" video series, we asked Raissa Bretaña to fact-check three outfits from Frozen. Upon evaluating Elsa's blue dress, she deemed it a "total fantasy" for 1840s Norway, the time and place that her Arendelle is modeled after. Bretaña also took a look at Elsa's coronation gown, and her younger sister Anna's costume—and, in both cases, she said the animators took a few creative liberties with the design.

Watch the full video above to find out how the fashion in Frozen compares with reality.