What is in this image? Describe it as if you were explaining it to someone from the 15th century.

Behold, a drawing that captures a peculiar and exhilarating sport wherein people, clad in strange, padded tunics, glide across the land covered in white powder, known by us as snow, using long, narrow wooden planks strapped to their feet. These persons are also equipped with poles to aid their movement. Whilst one man performs a unique feat of hurtling forward, flat upon his belly on a contraption akin to a small sled, he holds a stick that leads to a tube, which he directs forward as though aiming a weapon. This tube, however, bears no resemblance to a cannon or firearm as used in war.In the background, another participant propels himself using his sticks, his pose suggesting swift movement as he crosses a boundary marked by flags numbered distinctly as "3" and "4," suggesting this sport involves not just skill in movement over this frosty terrain, but also precision in navigating a set path or reaching designated points of passage. The scenery includes distant mountains and stretched clouds above, illustrating that this activity takes place in an expansive outdoor setting, possibly a valley.This tableau is a window into a ceremony of speed and skill, much different from the tournaments and games of your age, combining the serene beauty of nature with the thrill of competition.