In the animated movie Rise of the guardians, the character Jack frost wears a hoodie. All the others characters are depicted wearing colourful and relevant clothes. I wonder why Jack frost is shown wearing a hoodie. Is there a reason behind this?
In-universe, Jack is depicted as a perpetual teen with the official iPhone App pegging his age at 17 (for the last 300 years). Over time, he's clearly changed his look to emulate the young people he sees around him, including picking out age-appropriate clothes. I don't think we need to read any more into the actual hoodie itself other than that he probably swiped it at some point, presumably quite recently.
The writer of the source novel (and the film's Exec Producer), William Joyce offered the following pen&ink sketch on his instagram feed, implying that Jack has long been quite the dandy and an aficionado of hooded outfits (in this case made by the good elves of "Ye Oldie Outfitters of Urban Yore"), well before the 21st Century