I know even less about stained glass than I do about solar power.
But I don’t find James’s examples of great stained-glass art especially compelling. To my eye, the pure mandalas that are the great rose windows have an impact that far exceeds any representational image. I can’t find a good photo of the window in the cathedral in Prague, which kept me rapt for about two hours one sunny day twenty years ago. But here’s Notre Dame: