I'm not sure this is what the post is talking about, but I use visuals for myself when trying to figure out more complex queries--both existing ones someone else created and new ones that I need to create. I sketch the tables/views on paper with just the relevant information and lines. I (sometimes) find it very helpful.

Also, while not an image which: "condense information into a much smaller space.", I find giant, poster size printed data models (when laid out and color coded in a helpful way) to be very helpful in me being able to grasp or simply use a database.

As for helping business people find tools or methods to work with data: I'm mostly of the mind that the vast majority of lay people are not qualified (on a couple levels) to create their own reports. I think it is in everyone's best interest to have a professional put the reports together that the business people ask for. I think MS Access works especially well for this purpose because you not only get a great set of reports, but you can design an appropriately sophisticated user interface for accessing the reports. The need for a good user interface becomes more important the greater the number of reports that are needed.