A MUSE, ME Fernande Olivier must have been a heck of a girl. At least Picasso seems to have thought so between the spring and fall of 1909, when his imagination was so captured by her that he produced more than sixty heads, busts, and half- and full-length cubist representations of a woman in her likeness. Talk about flattery. This intense devotion to a single subject is rare, and on February 15 the Nasher Sculpture Center, in Dallas, dedicates itself to both the artist and his muse when it opens “Picasso: The Cubist Portraits of Fernande Olivier,” a traveling exhibit of about fifty works organized by the National Gallery of Art. Fernande must have felt every square inch of herself, well, cubed. (See Dallas: Museums/Galleries.)