The camera has its own language to tell a story.  The picture structure language is one of them. Different pictures structure has the different meaning. The symmetrical picture usually base on a line or a point. Shapes, color and sizes of things in two sides are usually same. The frame in this situation can make audiences feel quiet and serious. Thus, it uses frequently when people face life and death.

If there are two characters share the same frame, they normally share the same feeling. If there are two characters in completely separate frames, they are usually no relationship. If they have the relationship, OVER-THE-SHOULDER SHOT is a good choice.