Not necessarily. For example, if we used all circles in our art and if those circles were all different sizes, our art would have more noticeable differences, making it more interesting.

But what if the circles were all the same size? We could change the colors of each circle, making it more interesting because we would have differences of color.

But what if the circles were all the same size, shape and the same color?  We could then make them all different textures and that would be a very noticeable difference too.

Design and value are the strongest differences we can use. The most powerful way to show differences would be by making the circles different sizes and values, and placing them in different parts of the picture. Or, we could create differences and interest by using color or texture.

There are repeating shapes and repeating patterns. A repeating shape gives us some unity in a painting, but a repeating pattern is predictable. Our eye, and more importantly the audience's eye, doesn't bother to look at the rest of the pattern because we know what to expect. The best and easiest example of this is a checkerboard pattern. By disrupting that pattern, even a little bit, our eye will go directly there. Once we know that, we can control it.

 

Warhol