@gilliatt, it looks like you had fun with this!
But yes, @dwixer is correct. There were two assignments that were very specific. One was to write three paragraphs - describing the traits of each of the three characters as you imagine them from the bit of dialog. The other was to write your own dialog that is 70-100 words.
I see what you mean about the same thing occurring over and over if all of the participants follow those instructions, but actually no two writers ever come up with the same thing based on the same prompt.
It's okay. You wrote a story, and how can that be a bad thing? :-)