What does the dragon case on the relief mean?

Grand stone carving in the Forbidden City: This is the largest stone carving in the Forbidden City. It turned out to be a stone carving of the Ming Dynasty. In the twenty-sixth year of Qing Qianlong (176 1), the old patterns were chiseled off and re-carved. This stone is1657m long, 307m wide,17m thick and weighs more than 200 tons. This stone was collected from Fangshan. At that time, it was very difficult to collect and transport stones. During transportation, a well is dug every mile, water is poured into the ice channel, and it is consigned by dry boat. It takes as many as ten thousand people to collect and transport a stone. Around the stone carving, there are flourishing lotus patterns, the lower part is the sea water river tooth, and the middle part is carved with floating clouds, which set off the nine dragons and Zhou Long. Yunlong is vivid, meticulously carved and meticulous, which has high artistic value. Dragon is a miraculous animal in the legend of China. It is good at changing, arousing sexual desire and benefiting all things. It is the leader of scale insects and the head of the four spirits (dragon, phoenix, unicorn and turtle). There are many different images in ancient books. Speaking of slender, it has four feet, anticlimactic. Speaking of piercing scales, there are whiskers on the head and five claws. Compendium of Materia Medica says that "dragons have nine similarities", and it is a heterogeneous animal with the advantages of various animals. It has many names. Those with scales are called dragons, those with wings are called dragons, those with horns are called [multi-tower] dragons, and those without horns are called autumn. The little one is called Jiao, and the big one is called Dragon. Legend has it that it can be hidden, detailed and huge, short and long. The vernal equinox ascends to the sky, and the autumnal equinox dives into the deep, omnipotent. In mythology, it is the master of the underwater world (the Dragon King), a symbol of good fortune among the people, and the embodiment of ancient imperial power. The Chinese nation, also known as the descendants of the dragon. The dragon is a symbol of the Chinese nation. So in my opinion, the carving on Yunlong stone carving should be a symbol of imperial power, representing the emperor's supreme and unshakable rights.