Sigma 500mm, Nikon D800, f/5.6 @ 1/1000. ISO 400. Levels and highlights/shadows adjustments. Cloned out two dust spots and a darker area in the lower left.
It's either my eyes or the image is a little soft. I like the walking pose and the coolish colors. I find that the negative space is a little too much maybe one inch less canvas on the left.
It does seem a little soft, but what a lovely catch!! Did you sharpen the exported JPEG? It took folks here a while to convince me, but it does make a difference -- Smart Sharpen at the lowest Radius, Lens Blur setting, very carefully. But there are a lot of things that can soften an image at that much telephoto reach.