It’s a close detail from The Merchant Georg Gisze (1532) by Hans Holbein the Younger, in an image available via the Google Art Project. The before-the-jump image is a screen grab�a detail of a snatch of paint just about Georg’s nostril�showing how astoundingly closely these museum-quality scans let you peer into the paint. (The image at right is a screen-grab detail, too; go to the site for a complete view of the painting, which resides in Berlin’s Gem�ldegalerie.)
Audio commentary at the site explains that Gisze was a leading figure in the European commercial confederacy known as the Hanseatic League; he was 34 at the time of the painting.
As a former museum books editor, I don’t know what to make of Google’s Art Project�but as a person with eyes, I suggest you go and dig in; it’s deep.