The challenge is to write original, short fiction that can be read in less than three minutes — that's no more than 600 words. At some point in your story, one character must tell a joke. And, one character must cry.
To be clear, the character who tells the joke can also be the character who cries, and the crying does not have to be in reference to the joke. Just at some point within your 600-word story, those two actions have to happen.