What kind of expression technique did Li Bai of the Tang Dynasty use in his poem,"Su Tai Lan Gu"?

Li Bai of the Tang Dynasty used the method of comparison to express the poet's thoughts and feelings about history and life by comparing Su Tai with other places. The "Su Tai" in the poem referred to the hometown of Su Zimei in ancient times, while the "other" referred to other places. By comparing Su Tai with other places, it emphasized the long history and cultural heritage of Su Tai, and at the same time, it also expressed the poet's thoughts and feelings about history and life. The entire poem was filled with a sense of history and philosophical meaning. It was a classic work of ancient Chinese poetry.