What are the differences between Du Fu's three poems (Wang Yue, Wang Chun and Li Shihao) in genre and expression?

"Full Moon" was written in the Tang Dynasty, expressing the author's youth and frivolity.

Spring Hope was written in the early period of An Shi Rebellion, expressing the author's helplessness to the motherland.

Li Shihao, written in the later period of An Shi Rebellion, expressed the author's helplessness to the social poor, and also reflected the ignorance and anger of the society at that time.