Pattern forms when such elements as shapes , lines or colors repeat within a scene and it amplifies the significance of each individual element. When you have three or more similaar elements in your image , a pattern emerges. But i've never found that just three rocks , tress or blossoms or three of anything else , create a strong pattern , even if they are identical. By the same token , an image filled with a variety of patterns can lose impact. But an image of , say , a field of wild flowers in which only one or two types of flowers are repeated in your frame can be very strong.