The most controversial aspect of Alban Berg's opera Lulu-and one that has generated considerable criticism-is the composer's conception of the protagonist's character. Judith Lochhead, for example, argues that it is impossible to trace "a single, continuous feature that defines Lulu's personality." However, Berg offsets the "typological" element in Lulu's characterization by assigning her complex levels of interaction with her portrait, which is continuously present and symbolizes her sense of self-identity and her perception by others. Thus he changed several aspects of Wedekind's plays and created musical structures to represent Lulu as an individual and an object of desire. The most important of these devices is the music associated with Lulu's portrait, which marks significant dramatic and structural moments in the opera. Berg's extensive annotations in the opera's sketches, his copies of the plays, and the Particell bring to light the significance of Lulu's portrait with regard to her characterization. The portrait and its leitmotivic set pervade the opera, serving multiple functions according to the different dramatic situations. More than just an objective representation, Lulu's portrait is a constant reminder of who Lulu is in the opera. On the basis of this evidence, this study demonstrates that, by engaging the long-established literary tradition that associates women's identities with their reflected images, Berg makes the opera pivot around the portrait music, effecting a transformation in Lulu's sense of self-identity.