Goldman Sachs, one of the last bastions of crisp-collared, bespoke-suited workplace attire, has loosened up. It announced an official “firm-wide flexible dress code” earlier this month. And at last — after the long, slow undoing of corporate formality — business casual seems to have triumphed in the American workplace. But for women and minorities who have been playing corporate catch-up for decades, a more casual dress code presents its own complications. Women at work who feel pressure to prove they deserve to be in the room might be wary of ditching their blazers and pumps.