Good for you! I seriously highly recommend the movie hahaha and your comment is actually extremely pertinent, because the moment Timothee has his "realisation" at the end of the film, the skies literally clear and it is no longer "a rainy day in New York". It happens when Elle's character makes a silly comment which shows she doesn't understand culture/literature/the arts, which are Timothee's passions. It also shows she has no interest in growing or learning, and would rather brush over his feelings.
I will also say, Timothee and Elle in the film mirror the material situation and trajectory of Niomi and Joe's relationship so well. They are both from wealthy families, and have gone on holiday to New York together. They check into their luxurious hotel room, but it immediately becomes clear that they want completely different things from the city. Timothee is a wanderer who wants to integrate himself into the rich history of NYC and meet odd different people. Elle is a type-A clueless ingenue who is bustling around and ignoring all Timothee's genuine efforts to communicate with her. Doesn't want to do romantic or interesting things, only wants to check off boxes that will further some article she is working on (aka Niomi's vlog).
Also, Timothee is from an older-money family and feels stifled by his parents' shadows just like Joe. Elle is from a 'new' money family.
Guys the parallels are driving me insane! Every 5 seconds I think of a new one. Wouldn't be surprised if all this went riight over Niomi's head (just like it does Elle's in the film), but it MUST have clicked with Joe.
Everyone watch the movie, and comment your theories hahaha. If you're interested in this mystery of the missing Joey, you'll enjoy it anyway because it's the bloody movie version of this saga.