In a recent post by Matt Shipman, "Chart junk? How pictures may help make graphs better", he states, "Some experts describe these graphic embellishments as "chart junk," which they argue detracts from a graph or chart's effectiveness."
The "expert" he is referring to is none other than Edward Tufte, as that is one of his favorite and most-quoted terms.
Having been one of the fortunate ones who have had the opportunity to attend Tufte's seminars and read his books, I can tell you that while he may not condone the practice of gratuitously inserting graphic illustrations into demonstrative exhibits, I do believe he would understand and agree with the principles of proper layout, color usage and contrast to bring out a particular point.
Upon checking his web site, I noticed that he is offering some seminars in the coming weeks. I would strongly encourage anyone involved or interested in visual communication to attend.
I still recall when I found out that my former law firm (Brobeck) was sending me to this course, I was a bit disappointed, not really having an interest in learning more PhotoShop or PowerPoint techniques. In retrospect, I am so glad I was able to attend, and I rely on this material in nearly every trial in which I am involved.