The next sentence is "Smile for the beauty of the city"

In order to strive for the beauty of the city, I am willing to fall into the phoenix tree. The Indus River is a symbol of sadness; Autumn means to let go; Red means bright and colorful. If she is in sadness now, the last sentence means: I am willing to let her put down her sadness with beautiful things in the world. If she is not sad or smiling, then the last sentence means that she is willing to exchange her wings for something beautiful, just because your smile is as bright as when she is sad.