"The night left a thin layer of snow over the highest mountains [in] fresh air that is difficult to have in our cities." The mountain forms a waterfall and gradually flows to a lake, creating a water source for nature. Photographer Alessandro Mari uses a several techniques here, "Rule of thirds", the waterfall lays on the left side of the image, which occupies around 1/3 of the photo. In addition to that, he uses the different levels of lightness to produce overlapping layers. From left to right, the image become lighter and lighter.
Also, observing from the waterfall, we notice that the water seems smooth. I guess what the photographer did is to set the shuttle speed a bit higher that normal.
Here is the link to the photo: