The Los Angeles artist Laura Owens brings a light touch and a tough mind to a new kind of synthetic painting. Her exuberant, bracing midcareer survey at the Whitney beams a positive, can-do energy. As a stylist and culture critic, Owens is neither a stone-cold killer nor a gleeful nihilist, traits embraced by some of her peers. She’s an art lover, an enthusiast who approaches the problem of what to paint, and how to paint it, with an open, pragmatic mind. Her style can appear to be all over the place, but we always recognize the work as hers. Her principal theme may be her own aesthetic malleability.