The problem with the short quote is that it is not very memorable. That, and the fact that it seems too short; I think the quote could use improvement. The short quote, while indeed reveals an aspect of Kristoff's character, does not reveal enough. Now, the longer quote does better suit his article, as it reveals more about his character than the short quote does. I think the quote should reveal more about the character's personality, like the current quote does. I don't know if there's an issue with the length of the current quote, but there seems to be no specific rules about the context of the quotes. This also means that there is no limit to who is able to say the quote.
While I believe that the current quote better suits his article, I think that the second one fits as well. Sure, it may not reveal much about Kristoff's character, but it reveals more about his profession and is somewhat memorable. Like I said, there are no rules in regards to this issue, so I don't know the limits on the use of character quotes.