The stained glass forms a mosaic pattern.

This triangular window in the gable above the two east windows is typically “curvilinear”, but the tracery, like that in the northernmost of the pair below it, is a modern reproduction. The original tracery of this triangular window, of identical pattern, was removed as unsafe in the restoration of 1871-2, and may now be seen resting on one of the stone benches inside the porch. The tracery was, unusually, cut from a single piece of stone.¹

References
1. C H B Watson West Bridgford Church Transactions of the Thoroton Society 1941