What role does the sentence "Xing" in Guan Yu play in expressing the ideological content of poetry?

Xing: To arouse interest by holding things, first talk about other things, and then draw out the things, thoughts and feelings that the poet wants to express through association, which is equivalent to the current symbolic rhetoric. Xing means that the emotion is in an image, and the image is also an image, so Xing has the realm of self and selflessness, which can strengthen and deepen the expression of the ideological content of poetry.