What exactly does the girl mean by bitter gourd?

It means the most bitter thing in the world, and it is also used to describe the ugly face of people. As we know, bitter gourd is called bitter gourd because it tastes bitter and people have a very bright feeling when eating it in their mouths. It is also used to describe people. Like a person's face is ugly, often with a smiling face, and let others look at a sad face, so he is a little bitter gourd in the world, which means he doesn't have a smiling face.