What does Bai Juyi mean by "since the flowers are gone, there is no hibiscus in autumn water" in "Feeling the Mirror"

The beauty said goodbye to me and left the mirror in the box.

Now that the flowers have gone, there is no hibiscus in autumn water.

I haven't opened the box for years, and the red ai is bronzed.

Wipe off today and look haggard.

According to the heavy melancholy, I returned with a pair of dragons.

This poem is obviously a nostalgic expression of "beauty". "Since the flowers are gone, there is no hibiscus in autumn water", the mirror is left to the poet by the beauty when she leaves, and the first two sentences explain it. The following two sentences mean that since you broke up with me, you have never seen a beautiful face in the mirror, just like a graceful lotus on the water in the clear waves of autumn.

As for the writing background, there is no textual research. I can't know exactly who he fell in love with, but I know that he once had an unforgettable lover named Xiang Ling. Xiangling was the daughter of a neighbor who lived in R&F (now R&F in Su County, Anhui Province) when Bai Juyi was a teenager. However, due to the strict feudal ethics, neither side dared to make the relationship public, but only secretly exchanged views. Later, Bai Juyi left Liv, and both of them vowed never to be negative. Unfortunately, there was a more important reason for the separation at that time, and that was the concept of family. After Bai Juyi became a scholar, she asked her mother to marry Xiangling, but she was rebuffed. Bai Juyi can't resist this pedantic idea. Although he was in pain, he had to passively resist by never marrying. Finally, he got married at the age of 37 under the pressure of his mother. (Later, I ran into Xiangling. Both of them are in their forties. Xiangling has never married ... This is what I have always resented. ) They are predestined friends, but this unforgettable love always reveals the shadow of Xiangling in Bai Juyi's poems.

So I think this poem is also nostalgic for Xiangling.