Standing among the DKNY store’s iMac stations and racks of Technicolor ponchos, Natanel Gluska’s oversize “Long Chair” looks as if it had been found in a prehistoric cave. Gluska’s austere, rather unforgiving high-back seat – a Paleolithic version of the Adirondack chair? – has been chiseled, with just a chain saw, from an enormous elm tree. In the past, fans of the Swiss furniture designer had to settle for parking themselves on his signature rough-edged works in the lobbies of chic hotels like the Paramount and the Mondrian. Now, thanks to Karan’s growing interest in global lifestyles, shoppers can purchase the chair and Gluska’s raw-oak footstool – at prices (chair, $11,132; footstool, $982) that are decidedly modern.