Just to settle the argument. Screenshots are not a must when it comes to map submissions. We prefer when you do add them but that mainly is so we know whether we're judging the right course or not. If you don't have a screenshot, we'll just assume to have found the correct plot. It also helps lazy players to look at the map, without actually going to it in-game. Depends if you're really looking for replies or not. It also has no influence on the outcome.
I'd still recommend adding screenshots, they make your submission look nicer as well ;) So I hope this explains all.