This metaphor comes from the idiom "kill two birds with one stone", which means that one arrow can shoot two birds at the same time, achieving the effect of killing two birds with one stone. In the metaphor of "a woman eats two fish", "fish" represents a woman and "eating" represents two different personalities or behaviors. One kind of "eating" is eating fish head, which represents women's positive personality, such as being strong, decisive and independent; Another kind of "eating" is eating fish tails, which represents women's negative characters such as weakness, dependence and obedience. This metaphor is intended to show that women are diverse in personality and behavior, and sometimes they show two completely different personalities or behaviors, so that people can understand and know them more comprehensively.