PARK CITY, Utah — An annoying new comedy starring Natalie Portman and Jenna Ortega asks whether a corpse is art or not. A noxious influencer named Dalton (Zach Galifianakis) comes for a private tour of the Miami gallery of Polina Polinski (Portman), a deep-pocketed divorcee, during Art Basel. 3 Natalie Portman and Jenna Ortega star in “The Gallerist.” Courtesy of Sundance Institute. 3 Ortega, Portman and Charli xcx attend Sundance. Sedated-seeming though Portman is, her Polina is intense amid the haze, not unlike her Jackie O or her “Black Swan” ballerina.