A "hint of longing?", a "HINT of longing?"  It's more like an avalanche of teenage angst because your crush won't reciprocate! 

a melancholic song about unrequited love, especially because it’s all crescendo and no denouement: Listeners never find out if the main character actually gets her wish—much less if the person she’s confessing her love to actually feels the same way. “All I Want For Christmas Is You” is a one-sided confession of wants and desires, not a song describing or celebrating a consummated relationship. “Honestly, the lyrics, to me, come off as hopelessly sad,” Williems says.  “I’ve read the critical reception section of the song’s Wikipedia page, and I can’t help but think the critics weren’t really listening. One critic seems to claim there is a ‘hint of longing,’ which might be the understatement of the century.

If you wanted to get real bummed about it, I think the argument could be made that the song is denouncing the artificiality surrounding the spectacle of Christmas,” he continues. “Saying that you are so hung up on the negative of not being with one person on Christmas that you can’t embrace the joy of the holiday is really pretty sad, but also movingly honest for a pop Christmas song.

http://www.avclub.com/article/why-mariah-careys-christmas-hit-will-be-around-for-229110

Someone sort it out.  Who is Williems?  And why can't he/she spell "Williams" properly?