The TL;DR is that this is a friendly challenge to get you to write computer programs that create generative art. They give you a guiding prompt for each day of January – which you are free to ignore – and then you share your creations online. I'm “pinning” it here as something I'd love to do but at the same time I don't consider essential enough to actually carve out the time to do it during January... Maybe I'll get to one or two...