The Chelsea neighborhood in Manhattan is still Art Gallery Central, its origins dating at least to the 1990s, when low-rise warehouses and reasonable rents began luring these venues from SoHo. As with SoHo’s fate—by which escalating real-estate prices brought high-end retail shops and condos and shooed away galleries and artists’ lofts—the overwhelming popularity of the High Line along the west edge of Chelsea and the rapid construction of luxury residential towers could again demonstrate that economic gains come with cultural losses. But, for now, the mix is lively, even if many galleries are counting on the largesse of landlords.