What is the sign of the hornet's nest on the window?

The hornet's nest outside the window is a symbol of good luck in superstition.

The reason is that bees and phoenixes have similar pronunciations, and honeycombs are homophonic into phoenix nests, and phoenixes have been a symbol of good luck and wishful thinking in China since ancient times. So there is a hornet's nest outside the window, which indicates good luck and misfortune in superstition, and indicates that good things will often happen again and again in the near future.