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

This image depicts an underwater scene, a realm quite distinct from the terrestrial landscapes you may be familiar with. At the center, stretching across much of the picture, is an enormous leviathan or sea monster, resembling the mythical dragons often spoken of in lore and legend. This creature, however, has a more mechanical appearance, suggesting an artifice—a creation from the hands of man, like armor or windmills, yet shaped to resemble a beast of the sea.Surrounding this central figure are various forms of sea life and objects that might be curious to your understanding. Closest to the bottom, there is a chest, akin to those used for keeping a king’s treasury or a pirate''s loot, possibly filled with gold or valuable trinkets. Nearby, an octopus, a creature perhaps known in tales of sea voyages and exotic isles, crawls subtly along the sea bed.Floating above and to the sides, fish resembling those caught for sustenance swim about, while flora akin to plants—possibly seaweeds—are illustrated growing from the sea floor. Bubbles ascend towards the water’s surface, signaling the bustling activity and life within this aquatic tableau.Overall, the atmosphere captured in this drawing would impart tales of oceanic depths filled with wonders and mysteries, much like the fantastic stories of far-off lands or the abyssal plains few have ever ventured to describe in the tales of old.