At top is a simulated compound-eye view showing how a Great Spangled Fritillary Butterfly sees another Great Spangled Fritillary Butterfly from different distances. Eye-to-subject distances are: extreme upper left and barely visible 4.3 meters' distance, then 2.1 meters, 1.2 meters, 71 centimeters, 38 centimeters, and finally the largest image you see on the top right, at only 18 centimeters' distance.
Below is a simulated view at 7 centimeters (left), compared to the original photograph (right). At 18 centimeters a striking phenomenon occurs: if the “eye” or the subject moves slightly, large portions of the field of view seem to flash between all orange and all black.
It may be more than coincidence that 18 centimeters is about the typical courtship distance for this species. So the regularity of the compound-eye may act as a cross-correlation filter for the regularity of the spotted wing design.