A candid moment in the Oval Office has some Barack Obama opponents and residential purists up in arms -- all over a foot and the president's desk.

A photo, taken in August as the president spoke on the phone with Speaker of the House John Boehner, shows Obama standing behind the Resolute Desk with his foot perched on the edge.

Some conservatives are calling the photo and the president's casual look a disgrace, harkening back to when President Ronald Reagan wouldn't enter the Oval Office without a suit coat.  Others wondered on Twitter if the president ever was taught not to put his feet on furniture, let alone priceless antiques.

NBC, however, noted that Obama isn't the first president to put his feet on the desk, which has been used by nearly all presidents since Rutherford B. Hayes.  George W. Bush and Gerald Ford also were photographed kicked back with their feet on his workspace.  Ford was one of only three presidents since 1880 to not use the desk.  Presidents Lyndon Johnson and Richard Nixon were the others.