Compatibility: a pleasing or congruent arrangement of parts

Harmony

There is harmony in this arrangement with the shape and color. Without the shape it was in there would have been no harmony and would be a random arrangement.

There is harmony in this arrangement with the shape and color. Harmony would be lost if something like the shape of the arrangement was gone.

There is harmony in this arrangement with the the balance between the flower and stem. The harmony would be lost if one or the other was gone.

The scale of the container and flowers create harmony. If the size were different the harmony would not exist.

The scale of the container and flowers create harmony. If the size were different the harmony would not exist. Or if the flowers were to change harmony would be lost.