Rather than saying it's "just" a photo, I would say something more positive like "This photograph does not produce coffee."
And if you can't find a translator, send it in English -- there is bound to be around him who reads English. As long as you include the item number on the subject line so he knows it's you. Or this "Photograph takes better than the coffee the actual machine produces!" Doe aka Marnie Well, I don't like Expresso. ;-)
