There are some real technical challenges to this, the first of which is that we're a forum and not a posting service like Flickr or *shudder* Brickshelf. That means that images aren't an intrinsic or even required (well, outside our guidelines) for things in the Showcase.
And it's sort of a catch 22... we could make it more visual, but so can the presenters in there. Sometimes, it's just a matter of putting some more pizzazz into a post. And more than anything, if you want to see more life there, comment!
You know, if I see links to Brickshelf, more often than not, the first thing I click is the "Back" button.