How a story ends is even more important than how it begins. The final shot in a film is the director's stamp on the story. It's the lasting image that audiences leave the theater with, and cinematic history is full of some great ones. Movies like Inception, Casablanca and even the new film A Quiet Place all leave the audience with brilliant final images. One recent movie that ends with a much-discussed final shot is Star Wars: The Last Jedi. Rian Johnson's film ending with Broom Kid has been the source of much debate in an already incredibly divisive movie. But Luke Skywalker actor, Mark Hamill was a fan of the final shot and offered his take on what it means, saying:
What I love particularly was - and they didn't have to do this, because the movie's over - all of a sudden you cut to the stable and there's that little boy, he puts out his hand and the broom comes to him. It's so subtle, the first time I saw it I thought he just took it, but if you look he puts his hand out and it moves over for him, implying that yeah, she's [Rey's] the last Jedi... until the next Jedi. It'll go on forever, believe me. Long after both of us are gone they'll be making these films from here into eternity.
Like Mark Hamill, I think many of us thought 'Wait, did he just do that?' upon seeing the Broom Kid, whose name is apparently Temiri Blagg, use the Force to move the broom to him. This scene was interesting because it was almost like a second ending to the film, practically a post-credits scene that let audiences know about the success of Luke's sacrifice and the enduring existence of light side Force users in the galaxy. As Mark Hamill told GamesRadar, Rey is only the last Jedi for now. When he is Force-projecting onto Crait and making Kylo Ren look like an angry child, Luke tells his nephew that "I will not be the last Jedi." Rey becomes the last Jedi upon Luke's death, but like Luke before her, she will not be the final Jedi.
That the Jedi will continue on is definitely part of what Rian Johnson was saying with that final shot. The Force is part of nature, and thus Jedi can always rise. Their existence is impossible to snuff out because being a Jedi is not about a bureaucratic institution of intergalactic police, it is about those Force-wielders who can do something. They choose to help make the galaxy a better place.
With many of the choices Rian Johnson makes in the film, like Rey's parents being nobodies, he is also speaking to the fact that not only will the Jedi endure, but anyone can become one. This is an egalitarian message saying that you don't need to be part of a royal bloodline or immaculately conceived to be special and make a difference. The final shot of Broom Kid is a capstone on that message, but I think the reason people take issue with this is that it can come off as a bit overly saccharine and heavy-handed, and there is an argument to be made there.