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

This artwork depicts a busy port scene, likely of a grand city by the name of Copenhagen, a city of great importance in realms to the north. In the foreground, perched upon rocks by the water''s edge, is the figure of a mermaid, a mythical sea creature known in tales and lore, often described as having the upper body of a maiden and the tail of a fish. The background shows a series of tall, tightly packed houses that resemble those in large trading towns, where merchants and townsmen might dwell. Looming over the waves, there are vessels of a kind unfamiliar to your time one is a large ship with smokestacks and a rigid structure atop, unlike the masted ships of your era. This likely signifies advancements in shipbuilding, using mechanisms unseen and powered not by wind alone.There are also flags flying, and though the details are distinct from the banners of kingdoms you would recognise, they symbolize dominion and identity, much as the heraldry you are accustomed to.The name "Copenhagen" is inscribed prominently, suggesting this place is of notable repute, and the scene artistically captures both the mythical allure and the bustling life of this northern port, linking the familiar tales of creatures of the sea with the progress of mankind in architecture and navigation.