Re: digitalis with strange top

What your friend photographed is a fairly common phenomenon for terminal flowers of the Scrophulariaceae family. This is called a peloria or a peloric flower (from the Greek word for "monster"). Although as you noted they are not monstrous flowers in the usual sense of the word, they are different from what is normally seen. Peloria is defined as "an abnormal (often hereditary) regularity of structure occurring in normally irregular flowers". (Don't think about this definition too much or you may get peloric yourself!) In short, the top flower looks different from the bottom flowers, sometimes; and this trait is transmissible from one generation to the next.

You can find out more about the scrophulariaceae and other plant families at this site http://www.keil.ukans.edu/delta/angio/www/scrophul.htm.