The novel's main topic was usually about the person in the box because the person was experiencing some kind of predicament or danger and needed a plot to show their struggle and struggle. This proposition allowed the reader to imagine the environment and state of the person in the case, thus triggering the imagination and thinking of the predicament and danger. In addition, this proposition could also be used as a turning point in the plot, bringing suspense and turning points to the development of the story to attract the reader's interest. The person in the cover could also be regarded as a symbol of the novel, representing those who were oppressed, bound, and restricted by society. They were in some kind of inescapable predicament and could only protect themselves by pretending to be pitiful and evading. This kind of symbol could stimulate the readers to think about social issues and raise their sense of social responsibility.