It's like Koyaanisqatsi of 20s! It's miraculous! Awesome! It's all about the idea of a great city moving forward up-tempo but still having quite common problems of Germany's twenties poverty and exacerbation, nevertheless Berlin being one of the most fashionable cities of Europe of that particular time. But it's not the movie's main account. Its atmosphere was created by excellent cameraman work. The frame when a train moves right into you and then suddenly turns away is quite impressive. Never seen that advanced cameraman till Citizen Kane. I'd also definitely recommend watching Ruttmann's 'Lichtspiel Opus I ', an avant-garde animated movie created in 1921.