By 1974 he had painted 200 of these works, all showing an identical black circular ring on a white background. (museumpublicity.com)
The metallic rim on the front bottom gives the device a premium look, with the semi circular rings reflecting the light source. (phoneradar.com)
And Ptolemy thought there were multi circular rings centering around the Earth but Atheist and Scientist give him a pass on this as a noble try for an enlightened thinker which is still further from the truth than the Earth being spherical, circular or whatever. (religion.blogs.cnn.com)