Shadow as repetition

This picture shows an impressive shadow effect to me. l was attracted by the colour of this picture in the first sight. It completely showed the form of shadow clearly. In this image, the shadow looks like an extendtion of the object and the shadow becomes a part of it. The shape of shadow was reflected on the object which it just like a kind of a pattern on the object. Like the third one from the left hand side, the cube shadow was projected on the top of the bottom one. The shadow increases the density of the cube in a different way. The dark shadow provided a sense of depth in this work. Those images inspired me to think the use of shadow. What kind of shape can provide an effective shadow shape to link up with my model and environment. l also started to think about the use of shadow. How it can enhance the physically shape of my model. Whether l should use the shadow as a repetition or a pattern of the object.