A wizard in the group I DM for often used silent images to convey complex optical information quickly. In other words, he took a literal approach to the whole "show, not tell" routine. Instead of telling the other PCs what [some phenomenon] he had seen looked like, he drew them a picture. In the air. In technicolor, HD, 3D, animated.
He did this in a great war council once, creating an illusionary view on a city and the surrounding countryside, to give everybody something to look at and interact with. Kind of like a super-advanced sandbox table, complete with zooming and panning. Actually, the way he described what his illusions were showing sounded a lot like a 3D RTS.
He wasn't entirely "honest" in what he was showing, though. The war council was a bit divided on what sorts of actions to take to defend their city against the attacking horde of enemies. The PCs had rather specific ideas about overall strategy. So the illusions showed what was necessary to reinforce those viewpoints in the minds of the onlookers. The simple fact that the wizard had rendered the city itself in great detail made it seem plausible that the rest of what his "holographic battlemap" was showing was also close to reality.
Simply put, he hid an illusion within an illusion... great work by a creative player!