This humor in pansori is called jaedam sori, which means funny sound in Korean.
Upon hearing this, Heungbu's older brother, the nasty and greedy Nolbu, becomes jealous, and he breaks a swallow's leg intentionally.
Heungbuga is a moral story emphasizing brotherly love, with themes and ideas of cause and effect and retribution.
However, promoting Confucian ethics and morality is not the sole purpose of the story.
Behind this fairy tale, there is a theme that reveals a new realistic worldview that the common people have acquired - "existing conventions are futile" - through subjects such as fallen aristocrats who still try to maintain their status in the midst of rapidly changing social phenomena at the time.