He was a giant of 20th-century art, but that doesn’t mean Pablo Picasso needed a big canvas. Fourteen of his sketchbooks — some smaller than a CD cover — are on display at Manhattan’s Pace Gallery as part of “Picasso: 14 Sketchbooks,” marking 50 years since the legendary artist’s death. One of the tiniest books reveals a stunning self-portrait in pencil, with piercing eyes. The show comes at a busy time for Picasso news: His famed 1932 “Femme à la montre” (“Woman with a Watch”), portraying muse Marie-Thérèse Walter, just sold for $139.4 million in New York, the second most valuable Picasso ever sold at auction.