What kind of balance did edward weston use to create contrast in the photograph shell , 1927?

Edward Weston used the balance in difference in value to create contrast in the photograph 'shell',  taken in 1927. The shell was a medium sized black and white photograph image that featured a nautilus shell balanced within an abalone shell that rested on a semi-reflective surface. The shells are set against a plain, dark background with pale tones that shine against it thus showing the difference in value to create contrast.

it would usually depend on the genre that they would provide

answercouplet;