<p>“He’s from Hawaii, O.K.?” said Mr. Obama’s senior adviser, David Axelrod, who occupies the small but strategically located office next door to his boss. “He likes it warm. You could grow orchids in there.”</p>
<p>Thus did a rule of the George W. Bush administration — coat and tie in the Oval Office at all times — fall by the wayside, only the first of many signs that a more informal culture is growing up in the White House under new management. Mr. Obama promised to bring change to Washington and he has — not just in substance, but in presidential style.</p>
