A second-rate Italian portrait of a woman, recently cleaned at the National Gallery in London, turned out to be a first-rate picture by Pordenone and a totally unexpected subject. The cleaning disclosed that the face had been repainted in the 19th century when decorum and sentimental prettiness were more admired than authenticity. The eyes, originally narrow and cynical, and the expression, hard and calculating, suggest that the suhject was a courtesan drawing aside the window curtain to display her charms. Such subjects were favorite ones of the 16th century Venetian painters. -- AATA