Not completely sure I understand but I'll try to respond to the best of my ability!
I don't think I can insert an icon from game-icons.net or have something like that, but I think having some pre-made options for buildings or terrain elements could be fun, and users could put their own pixel-art stamps in a folder in the downloadable version perhaps. Not sure if adding a heraldry stamp / generator would work with other genres besides fantasy but... maybe someday? (: