I get what where their coming from. I just misunderstood the exact nature of this jam myself. But its still a neat idea. However, I also do not use twitter, like at all. So email would be my only option, and that may prove... challenging for privacy reasons. But I'll keep an eye on this jam, if not to join, to at least see what people make.
Though I kind of wish the art here had prior permission from the artists to be used this way by all participants, it... well that only seemed logical to me. That may be a thing that happens in other jams later though.