The materials of ancient poetry are varied, so it can be said that everything in the world is poetry! Everything in the world is a poem, which comes from Zhang Jie's Poem of Cold Hall in the Southern Song Dynasty: Li Yishan's poems only know that there are golden jade and dragons and phoenixes, Du Mu's poems only know that there are flowers and bees and butterflies, but Li Changji's poems only know that everything in the world is a poem.
The meaning of this passage is not that everything in the world is poetry, but that "everything in the world can be used as the material of poetry". Conversely, everything and phenomena in the world can be used as the material of poetry!