This photograph still gives me goosebumps. The position of the horses, the wide-angle scale of the foreground the colours, the sense of occasion - all of it added together allows the image a surreal quality.
The light in the square bounces off the yellow brick buildings (Sienna the colour was named after the clay from the area after all). The wide angle lens accentuates the elements closer to the camera - it's all explainable though science, but that doesn't matter. It's a moment captured which I feel gives the occasion the appropriate level of grandeur.