This is an experiment is capturing a spider web that was almost perfectly cross-lit. This is illustrated by the shadow of the spider on the face of the web. By moving around, I could adjust the reflection of light in different areas of the web. With the light focused on the lower left hand side of the photo, the circular web is evident, but it fades away from this corner. This sets the focus on the spider. The reflection on the web also is changed by the spider tugging on it as it weaves new strands.
This composition also conforms to the rule of thirds, but the subject itself is novel. I cropped it to a square because the web was round. Round subjects (radial subjects) lend themselves to square frames.