This is not to say that just dumping an image on its own is a good idea, but an image followed by a brief explanation is often much more effective than text alone.
What about self-assembly kits (i'm thinking IKEA furniture here)? With just words, how would you put it together? But, same again, how would you do it with only pictures? The most effective combo is picture with a brief or simple explaination (not that I'm saying you have to). Ideas and instructions are best illustrated and explained. Even with a large vocabularly there are just some things you can't describe or are lost in translation.