>>4168026Two by two originated on twitter. It's their standard format for bulk image upload, a lot of people are using it as creative tool. Three by three was /tv/ thing for uploading screens, but it's rare there now. Somewhat recently one anon did some really creative 3x3's using short clips as webm. They were even posted in /vid/ here, but obnoxious namefags destroyed that general for good, so nothing more was seen from that.
It's effective tool for practicing coherent storytelling and style. But I guess that it's slightly on the complex side regarding utilisation.