You suggested in your description: "This works very nicely when you incorporate it into an infobox template making the infobox image the preferred image for 3rd parties to use"
How?
I tried to include it into my infobox: http://www.spd-geschichtswerkstatt.de/wiki/Vorlage:Person Yet the main image isn't set: http://www.spd-geschichtswerkstatt.de/wiki/Franz_Th%C3%B6nnes