My bad. I'm not a a native english speaker and I did learned my english reading D&D books, no proper schooling or anything
By "render" I mean Rob got my image from Paizo and he re-draw (I'm not sure if this is the proper way to say it) the whole thing again with his own style and tools. The map you'll see in The Serpent's Skull #5 book is a complete new map based on this illo.
My work here was to design the city map. James Jacobs gave me a small description of what he would like and I started from scratch. He asked for a finished map (all nicely colored and all, no tags thou) for a better reference for the authors. Also, this map was given to the authors for reference when writting about this places. Normally the author of an adventure does his own map and this sketch is given to the cartographer to do the city. In this case James added a "third party" to do the city design.