King and czar

Or is it czar and king?

Czar Nicholas II of Russia and King George V of England. Their portraits appear on many postage stamps and it is difficult to distinguish between the two men. Can you pick who’s who from this photo?

There's a 50:50 chance you're wrong - and if you're really smart (and observant, and knowledgeable re clothing and style), then you're even more likely to get it wrong, for a reason posted with the answer at The Ornamented Being.