while the Art Team is solving the difficulties with the image acceptance/declining, I have a doubt on the degree of actual customisation of the NPC images that can be submitted.
Given the rules of black background, exact race, sizes etc, as listed in the Exchange CPs page, I wonder if it is possible to submit an avatar which has the SWC combine frame PLUS a personal logo or diagonal band in a corner, to mark that custom NPC as belonging to a faction/NGF/Party, whatever.
To be clearer, in the SWC forums we see PC avatars that don't have the SWC frame but personal logos or vertical/horizontal bands with the name of their faction. Now, would this be possible for the image of a custom NPC too, provided that the SWC frame and the black background is preserved?
You can put your faction logo on the clothing of the NPC if you wish to try and differentiate them, maybe change the colour of the clothing to match that of your faction, but nothing cna be added outside the boundries of your NPC.