"Song of Eternal Sorrow" uses romanticism at the end, please analyze it concretely with poetry.

The fourth layer, from "there is a Taoist who lives in Lingqiong" to "this worry is endless", describes that Xuanzong sent alchemists to find Yang Guifei's soul, focusing on her lonely and sad memories of her past love life. The poet used romantic methods to go from heaven to earth, and finally let the imperial concubine reappear the fairyland on the illusory fairy mountain with the image of "tears running down her sad white face like spring rain hitting pear flowers". The catharsis of "emotion" has gone beyond the emotional entanglement between emperors and concubines, and is more of a poet's subjective ideal element, which has already gone beyond the scope of historical facts, showing the contradiction and conflict between subjective desire and objective reality. At the end of the sentence, "the earth lasts forever, and the sky lasts forever; One day both will end, and this endless sadness will last forever "is the sigh and cry of love." It is a lament that love is spread by fate and destroyed by political ethics. This hatred has transcended time and space and entered an infinite realm. In this way, the poet expressed eternal love with "everlasting regret", that is, pointed out the theme of the whole poem.