The idea is that the story is not planned, it evolves. So, if one writer or artist introduces a character or theme the next writer or artist can develop it, or not, as she or he chooses, as long as there is some kind of coherent link that makes it 'readable' (in the broadest sense of a readable 'text').
The idea partly came from a party scene in Louisa May Alcott's Little Women, where characters' personalities are developed, and contemporary reading habits explored, through a joint storytelling game. I was thinking along the lines of Pynchon or Rabelais or Perec or something anti-novelistic when I thought of doing this, but perhaps an avante-garde soap opera could also be an apt description. I am reminded of a drawing game I learned in primary school where each child draws a section of a body, folds it over to conceal it, and passes the page onto another child who contributes the next section, and so on, until the page ends and an inconsistent creature is revealed which doesn't conform to any kind mould other than that the pieces fit together. Also think: serial, like Dickens or Conan-Doyle, where each contribution to a larger story is written periodically (The Pickwick Papers), or each short story contributes to a larger reality (the myth of Sherlock Holmes), but with different authors (as in a television series) and, of course, with different media.
Illustrators, digital artists, graphic novelists, photographers, cartoonists, poets, writers of any genre, scriptwriters, non-fiction writers, copywriters, painters, embroiderers, sculptors, artists of any description are welcome and encouraged to participate.