And game is, indeed, the word; no living filmmaker pilfers from himself more playfully or prolifically. In “Bitter Christmas,” Almodóvar, perhaps in a burst of Yuletide generosity, has seen fit to give himself not one but two fictional alter egos. The first is Elsa (Bárbara Lennie), a Madrid-based director who has two little-seen independent features under her belt and who now works mostly in advertising.