the Sunset is beautyful, isn't it?

A poetic form of saying Goodbye to someone you cared about, you loved once or to someone you still do but can not have.
If the sun arrived it also means that the night will come soon after. So the day is going to end.

It's also a reminder that it shouldn't be a sad goodbye because there would also be many beautyful memories as warm as the sun.

"The Sunset is beautyful, isn't it?", she asked with a little Smile on her face. But her eyes looked sad. "Is it but sadly it can't stay forever up there." "Then, it's simply a goodbye", she laughted. "Right?"