I remember that hellenistic refers to the era, you can mostly see it in their statues. There were three times, one was wheir primitive look, which was copied off of the greeks, then came the 2nd look (which I forgot what it was called), then finally, Helenistic, where the statues had well defined muscles and postures, etc...
(Trivia: Helenistic statues influence the American view of the perfect body greatly, as the greeks popularized the idea of defined muscles)