The photos show Oliver in a uniform very unlike his standard green leather and hood; instead, he wears the faded brown-and-black outfit seen on Ra's al Ghul's League of Assassins. Since Oliver was offered the position of Ra's al Ghul and subsequently blackmailed, the photo could indicate his final decision come the season finale. However, it's also possible that Oliver is wearing said uniform as a disguise.
Check out the photos below and decide for yourself whether you think Oliver will accept the role of Ra's al Ghul.
"The Flash" airs Tuesdays at 8 pm EST and "Arrow" airs Wednesdays at 8 pm EST on The CW.