At the Olympic Restaurant on the Lower East Side of Manhattan, customers who heed the call of nature are in for a pleasant surprise. The grungy stairway leading to the second floor is ominous, but on opening the door to the unisex lavatory, they will discover a clean, well-lighted bathroom with the black tile floor, sleek stainless steel fixtures, dark wood wainscoting and gleaming white sink of a high-end corporate washroom. It is a work of art -- not just figuratively, but literally. Called ''Power Toilet / J.P. Morgan Chase,'' it is a fully functional copy of an executive bathroom at that investment bank's offices, created by the collaborative art-making group Superflex. The Superflex bathroom was unveiled last Friday as part of ''Living as Form,'' an enthralling, philosophically provocative round-up of 20 years' worth of socially engaged art. Organized by Creative Time's curator Nato Thompson, the show is mostly housed in the raw, cavernous interior of the Historic Essex Street Market; the Olympic occupies a corner of the same building. [ABSTRACT FROM PUBLISHER]