Giovanni Bellini's signed and dated painting of 1515 in the Kunsthistorisches Museum, Vienna, has long puzzled art historians as its generic title, Woman with a Mirror, suggests. Painted in the year before Bellini's death, the picture is one of a few non-religious subjects in a long, distinguished career of an artist famous for altarpieces and other devotional works. The patron and the circumstances of commission of the Woman with a Mirror are unknown. The painting's indeterminate title reflects the difficulty of deciding whether this beautiful female nude represent a real woman, the mythological goddess Venus, a Christian allegory of vanity or luxury, or all three at once.

I argue that Bellini clearly signaled his intent through his prominent signature, "Joannes Bellinus faciebat". Bellini used the celebrated signature formula of ancient Greek artists highlighted by Pliny's Natural History: the choice announced Bellini's aim to paint a nude Venus that surpassed any created by his predecessors, ancient or modern. Whereas the few earlier artists who adopted the signature had used it on religious works or portraits, Bellini matched it to the cognate subject matter of the idealized female nude, which was a traditional hallmark of Greek art.

This article analyzes several other features of Bellini's painting that substantiate the theory that the artist was depending on the Natural History and intending comparison to Pliny's descriptions of the nude Venuses created by the great Greek artists, Apelles and Praxiteles. It concludes with an examination of the techniques by which Bellini introduced ambiguity, specifically the nude's contemporary accessories and Bellini's reference to celebrated images of nudes by van Eyck, deliberate choices that evoked contemporary debates about the paragone and extended his old-age challenge to the world of contemporary artists.