Adults who get Halloween trick-or-treaters to their door, know Frozen.
A college classmate of mine wrote the song, but I could identify zero details about the movie and I don’t think I’ve ever even heard the song.
If you’ve never heard the song, you haven’t been out in public much. You may not have realized you were hearing it, of course.
For the OP, and other students: popular culture references are a bit dicey, because something that means a lot to you can mean nothing to an admissions reviewer, or even be a negative. Pop culture touchstones change–for you it might be Frozen, but for the person reading your application it might be Mulan (if she’s my daughter’s age), for example.
This is another reason why you should ask a couple of sensible adults, including some outside your family, to read your college essays to see if they make sense, if they have any false notes, or if they have any references that an older reader won’t get.
I don’t even know the names of the characters, let alone the plot.
I doubt my 23 yr old son knows anything about Frozen, either. He’s not a movie goer and definitely not a Disney movie fan.
And my daughter, who is 21 and not 5, can recite the entire movie, knows the songs, knows every trivia point about it. Her dream job would be to be Anna at Disneyworld.
If the reader of the essay doesn’t know Frozen, would it matter? What if the essay said “Disney’s Cinderella” or “Star Wars” or “Ice Fishing”? Isn’t the essay supposed to make sense to anyone reading it, not just those ‘in the know’?
I live in Asia and I haven’t been out in public much–I work a lot, haha.
You probably belong to The Lion King and Pocahontas or Kungfu Panda generation. 
Dunno anything about those either. Wanna talk about Bela Tarr or Alejandro Jodorowsky? 
(Actually, I did see The Incredibles, and even liked it)
Frozen? I know it exists and that today’s little girls are obsessed, but that’s about it. OTOH, I can practically recite entire sections of The Little Mermaid…
@marvin100 Did you go to college with H or W?
Guess OP is gone and will do what she/he wishes. I just can’t see alluding “to it being a movie, and mention(ing) some background story details + Anna&Elsa’s names,” when it’s for a college admit review. It feels like OP’s missing the point.
@jonri - Kristen Anderson-Lopez
I know OF Frozen, and I know (now that you reminded me) of the name Elsa, but not Anna. “Let it go” is the only line I know.
or you can be more erudite and use the original story, Hans Christian Anderson’s “The Snow Queen”
@bopper The stories are VERY different!
I know it’s a Disney movie but that’s about it. Most of the Disney movies in the last twenty years didn’t appeal to my boys and I’m not a huge fan of animation…Just say “Disney” and hopefully you can make whatever point your are trying to make.
I think admissions officers can be expected to know some things that you don’t have to explain, like that Friday is followed by Saturday, but I do not think they should be expected to know anything specific when reading an essay. I wouldn’t expect them to know anything about Disney or Star Wars or Jane Austin or weather in England. The essay is supposed to contain the information you are using in your essay.
I am surprised that no one has commented that it seems like a pretty juvenile reference for a college essay. I mean, my college kid does know what it is, but really would have thought twice before mentioning it in an essay. Just another viewpoint…