Answer:
The interweaving of different values allows for shapes in a picture to not make others invisible (for example, a dark shape placed in front of a large dark toned shape), and give recognizable shapes. When dark shapes in a picture are separated, the picture may look a bit "spotty". Dark shapes being combined together to make a new unified shape, as individual objects are still visible enough for recognition, a picture will look much more unified.
Explanation:
