Bri’s review published on Letterboxd:
The Please Mr. Kennedy scene has a moment that I love more than any other in the film. As they play this fundamentally silly (but super catchy song), we see just how tightly Llewyn and Jim click together in their guitars and vocals. As we watch Llewyn's face we see him recognize this, he smiles slightly and just generally looks exuberant as he plays. It's a song he just mocked to the man who wrote it moments before but, at this point, despite himself, he is having a fucking blast.
It's one of the most important parts of the whole movie to me (along with him finally thanking someone, telling them he loves them, finally giving an apology that sounds sincere and playing two specific songs close to the end of the film). It shows that he has an ability to connect to someone else. It also is just a great visual proof of that beauty of creativity and that exhilaration. Even when it's kind of a goofy song.