The special thing about this photograph is in the small details. At the bottom of this page is the whole image in a window where you can zoom in to see those details. The water drops coming off the splash are vibrating, making coloured dashes and dots as they move during this relatively long exposure. The waterfall was in a dark corner of the forest, but a few rays of sunlight peeked through the tree branches giving a spotlight that makes the water drop vibrations visible.
The computer background pictures linked below are crops from the image to reveal the interesting water effects.