Why does pony suddenly bring up the sunset when he is talking to Cherry what is he trying to say?

Ponyboy brings up the sunset during his conversation with Cherry to highlight a shared experience and connection despite their differing social backgrounds. He uses the sunset as a metaphor for beauty and commonality, suggesting that they can find common ground beyond their gang affiliations. This moment reflects his desire for understanding and unity, emphasizing that despite their differences, they can appreciate the same things in life.