It was just a year ago that Zephyr Dance member Andrea Cerniglia debuted her own company, Dropshift Dance. But this young choreographer already shows a rare confidence and self-possession—qualities she seems to have passed along to her performers. Dropshift’s “Push: New and Revisited Works” features a 45-minute premiere, Becoming, that opens with Cerniglia dancing an authoritative solo in a big, open performance area. But the focus soon shifts to a raised stage behind her, where four other dancers lie face down. One by one they begin a long, methodical approach to the audience, using a single repeated, hypnotic motion: still on their bellies, they flip up their hands, hoist their bottoms, then arch their necks and chests up—and scoot forward. Ever so slightly. They look like dolphins slo-mo surfing through waves. Eventually the four attain the apron of the stage, slide down from it, join Cerniglia, and begin to explore portraiture in movement. At once serene and provocative, Becoming marks Cerniglia as a talent. A duet from last year, Mine, Yours, opens the program.