Petrus Christus, The Virgin and Child with St. Barbara and Jan Vos (also known as "The Exeter Virgin"), ca. 1450. Oil on panel, 7 5/8 × 5 ½ inches. Staatliche Museen zu Berlin, Gemäldegalerie
What could be more appropriate for the Christmas season than an image of the Virgin and Child? And here is The Frick Collection, giving us not one but two fine versions of that subject, in "The Charterhouse of Bruges: Jan Van Eyck, Petrus Christus and Jan Vos" (though January 13).