First, "unique material" means that a poet should have a unique talent for poetry creation. It should be accumulated in books and theories, but it should be high in the realm of articles and righteousness. It is a manifestation of "wonderful understanding", not a manipulation and preaching of articles and principles.
Second, "otherness" refers to an aesthetic taste and artistic realm that requires self. It is an expression of aesthetic characteristics, which is caused by the poet's "interest". Therefore, most poems in the prosperous Tang Dynasty are based on it and have rich and meaningful aesthetic interest, which is very different from the truth and argument in the Song Dynasty.
Thirdly, poetry should have the characteristics of "infinite meaning", that is, the language of poetry can be perfect and plain, while the artistic conception of poetry is endless and interesting.
Influence: Yan Yu opposed the bad tendencies of "taking words as poetry", "taking discussion as poetry" and "learning as poetry" in Song poetry with the theory of "different materials" and "different interests". Put forward is to have artistic conception and the poet's own aesthetic taste. We should be "open-minded" rather than "disciplined" and have "other materials" rather than fiddling with words. It provides a reference for later generations' poetry creation.