Image A shows an example of a repetitive pattern design, where a unit is repeated in a pattern that is organized within a grid structure. In image B, on the other hand, there is a single unit which is not repeated but which is designed in a figure-background relationship. The pattern in image A could have continued on any side if it was meant to be larger, yet the dimensions that frame the design in image B is definite and meaningful in terms of the proportions of the figure to the ground, therefore would be difficult to change.
In the image A, there is repetitive pattern design that was used rectangle shapes and their varitations in terms of size and also you can predict the other steps that are not involved in this composition.In Additionally, it was organized within a grid structure.In the image B , we are able to see one single unit that has a two rectangles that they are variation of each other in itself.It is just single and there is no repetition. Because of that It is easy to comprehand and your eyes will not try to catch any continiuty in composition whereas in the image A there is continious flow, you will catch that point and are able to anticipate the next steps.
Semihcan Esin 