"She sent out for one of those short, plump little cakes called «petites madeleines», which look as though they had been molded in the fluted scallop of a pilgrim's shell." Marcel Proust goes on to describe the pleasurable sensations of eating a madeleine, "so richly sensual under its severe, religious folds" in memory- and thought-evoking detail, a spectacular feat barely accomplished with plain a picture of madeleines.
Often, a simple image is more practical and efficient than words, however — when you try to explain what error you see on a computer screen, for example:
›› Would you like to impress tech support in a helpful way? Instead of having to describe what wrong and ill you see on your screen, capture and send it easily with an email.