From 2013 on, prominent cultural figures joined Hockney friends and family as portrait sitters at the artist’s brightly colored Hollywood Hills home and studio. There are portraits of his studio assistants, massage therapist, housekeeper and cook. Others depict Hockney’s siblings, the children and grandchildren of his friends, and art dealers such as London-based David Juda, New York-based Larry Gagosian, L.A. Louver’s Peter Goulds and the Ferus Gallery’s Irving Blum. So how did the pictures turn out? Very few sitters are smiling — it’s hard to smile for 20 hours — and Hockney says he has no idea of how they felt about their portraits.