Art to See in the Galleries From Caged Dolls to a Floating Pool in NEW YORK CITY’s grand gallery mosaic keeps expanding, and pieces keep moving around. Veteran Chelsea spaces decamp to an already gallery-dense Lower East Side, or open franchises there. New arrivals refresh the stately Upper East Side, and artist-run start-ups create vibrant, if fragile, art neighborhoods in Brooklyn. For an art lover this means a confusion of riches, not just of places but of things. In galleries right now you’ll find — along with lots of painting — miniature theaters, an indoor pool, a chairlift, poetry-writing clocks, feature-length films, telepathic emails and an entire library of books that should have been written but weren’t. Keeping track of such variety takes work. A gallery sweep that a single critic for The New York Times might once have managed over a long weekend now requires several writers fanning out in different...