Wow, I thought I answered this one....must have forgotten to hit Post....

Anyhoot, back to topic at hand. I think this could go either way; a picture chosen by the CLs or by the artist, as long as the picture and map match on some key points of reference. How many points would be up to the CLs, or if a CL picture, which points. For example, if the linked picture was used, the CLs could say that the rock outcropping in the foreground, the one on the left and the two smaller ones in the middle could be points that are required on the map, maybe even including the stream passing through the whole thing.