How did the super-long shot in flowers of war come out?

I think this long shot is more advanced than the first long shot, not advanced special effects, but advanced space exploration. Why use a long lens when you can shoot from two directions? The reflection of the mirror in the long shot makes the picture appear absurd because many people's faces can appear in the same picture at the same time, but in the barber shop, the mirror is this kind of decoration, which is meaningful and increases the film and television effect. At the same time, this long shot is also very difficult to shoot. Actors need to know their position at all times and remember their standing posture in order to appear in the camera. This long lens can restore the real world, just like the world we see with our own eyes. What a powerful director is best at is to restore the real world in a unique way, which is the art of images. I hope there will be more directors with high standards in film and television, not just movies.