Definitive proof this week that ours is a divided world. The globally significant matter in hand is that of the dress code for Oscars night in Los Angeles on Sunday. Here was the ultimate game of two halves. Or, to be more accurate, in the case of the night’s second-hottest ticket, the Vanity Fair afterparty, a game of both halves. Because the so-called naked dress — the most modesty-agnostic phenomenon in 21st-century fashion, leaving almost nothing to the imagination — was out in force.