1. "Phoenix spreading its wings" means that the phoenix flies and dances in a beautiful manner. In ancient times, it was used as a metaphor for auspicious signs and auspicious sensations.
2, sources:
(1) "Han Book - Wang Mang biography": "Manna from the world, sweet springs from the ground, the phoenix came to the ceremony, the gods descended set."
(2) "Shangshu - Yiji": "Xiao Shao" nine into, the phoenix comes to the ceremony."
(3) "Romance of the Three Kingdoms", 80th time: "Since the King of Wei assumed the throne, the unicorn descended and the phoenix came to the ceremony."