My take on this is that watching people complain about an image breaking the TOS is marginally more entertaining than watching people being indignant that one doesn't.

One previous example -> http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2660683

Maybe the admins could do an infographic like the one for thumbnail nudity (-> http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2761249) to illustrate what's allowed and what isn't.