Sometimes a prototype is about getting the feel of a system. That's what card games are really good for. Sometimes, though, you just need an image that punches someone in the face with the "emotional" hook of what you're doing. So sometimes you need an extraordinary concept artist. I worked with Pat at a previous job, and he's a busy guy - you can check out his stuff at www.phattro.com, and if you're not impressed by that, then... uh... you've got... art something? I don't even know. We'd made a pitch a while back for a sci-fi extravaganza that never got past the pitching process (in part since the company we were pitching it at went kablooey shortly thereafter). But my enduring love for that project was in large part because of the way Pat brought the ideas to life through his art. (A number of other artists were also part of that pitch, and their contributions were equally fantastic - don't think I've forgotten!!)
But in any case, I went to him with a vague outline of what I'd wanted, and what he came back with was so far beyond what my puny imagination could have imaginated that, well... hopefully it says something to you, too:
Now combine that with the card game, and you've basically got what we're working on. All makes perfect sense, right?