Which Gatsby movie (1974 or 2013) best portrays the book and why?
As is usually the case, the older movies are truer to the story lines of the novels or plays that they portray. Added to that, producer, director, and screenwriter Baz Luhrmann is known for modernizing movies in which he is involved, feeling that doing so appeals more to modern audiences. Thus, the 2013 version of The Great Gatsby has costumes for the women that display much more decolletage than was revealed with the clothing of the Roaring '20s and the men's pants have narrower legs than was the case. Then, too, there are more "intimate" scenes of Jay and Daisy than in the older movie; they talk of running off together, they make love, etc. whereas in the novel more is implied that is explicit. In addition, Gatsby's house is modeled after a French hotel de ville with Marie Antoinette rooms, and in the 2013 version, although the interior is resplendent, it is of a different style, and the outdoors even more aggrandized.
While there are some scenes added, and Nick Carraway writes his story as a therapeutic exercise in a sanitarium where he is being treated for alcoholism, (and later returns to the sanitarium) Luhrmann does succeed in creating a motion picture that has more life in it than the 1974 version which is truer to the plot. A New York Times movie review criticized the 1974 version, stating that there is more to movie making than strict adherence to plot.
Francis Ford Coppola, who wrote the screenplay, and Jack Clayton, the director, have treated the book as if it were an illustrated encyclopedia of the manners and morals of the nineteen-twenties instead of a short, elegiacal romantic novel whose idiosyncratic beat demands something more perceptive from the movie makers than mere fidelity to plot.
Perhaps, then, the Times might find the 2013 version truer to the spirit than that of 1974.
The older movie is closer to the books. Occasionally modern movies can get pretty close to the books, such as with Hunger Games which was fairly close. The newer movie however had a lot of flair and fluff added because the director is very known for trying to make his movies seem over the top and unrealistic but in a beautifully artistic way. Because of this, certain things are left out and others are added in, to create this artistic portrayal of Gatsby.