Sidney Lumet, who just died at the age of 86, was probably the most famous of the first generation of TV directors to move into film -- him or John Frankenheimer. In a Hollywood where movies had come to look stodgy and static, he was one of several young directors who helped bring a new vitality to visuals and performances in Hollywood film.
A lot of his early movies were based on stage or TV properties, didn't have a whole lot of money to work with, and featured long static speeches. Many directors, then and now, think the only way to make something like that "cinematic" is to open it up, take it outside, find something to break up the monotony. Coming from live TV, Lumet understood that one person standing in a room giving a speech can work extremely well on the screen, as long as the performance is right and the camera catches it in the right way.
So it is in this scene from The Pawnbroker, one of Lumet's most influential movies (not just for getting Production Code approval for nudity, and thus pushing the Code one more step further toward complete collapse). Lumet was rightly acclaimed for getting the very best out of Rod Steiger, an actor who could go over the top unless he was extremely well directed. But he also catches this speech in a long take that doesn't have any sense of show-offiness. It's a long take that's claustrophobic and, once it settles on the medium close-up of Steiger, increases the intensity of the scene by its refusal to let us take our eyes off him until the speech is over.