It's kind of a strange thing. I'm finding that when you apply a base image that connects only loosely with the meaning of any given card, it actually kind of lends depth and breadth to the card meaning. Just so long as it's close enough. You get too far off base and it's just a miss. But if you're close enough, it opens the card up. It's hard to know sometimes when you're in the middle of a design whether or not you've hit close enough to the target, or if it's just a miss.
-- Frede.