Most stock images are descriptive: search for "ice cream truck" and you get what you asked for. The position the image puts the audience in, is at least as important (maybe even more important) than the object it represents. Look at this image of the inside of the Notre Dame cathedral in Paris (Wikipedia link). Six images stitched together to create the sensation of small child looking up to the ceiling of this vast place. It puts the audience inside the image.
Image credit: eso-teric, visit his site for a larger picture. I linked to these images as a source of inspiration (earlier post), check copy right restrictions before using them in an actual presentation. Found via TwistedSifter.