I'm very glad to know that you like the poem. I like it, too, but I was worried that it is too difficult for our class.
Yes, the poem is about the relationship between art and nature. This can involve some abstract concepts, but then we can also be concrete about it. I like the way you describe the relationship -- "Both of them should be existed peacefully. Art leads nature, and lets nature have more orders and rules. In other words, nature helps art, and lets art have another original beauty." Here we can think of those impressionist paintings, or other paintings about nature, which can all serve as good examples.
And we can also talk about this in terms of art and life, right? In this sense, "Musee des Beaux Arts" will serve as a good example.