In this picture, a sketch of a quadcopter is displayed with rotor's direction of motion. The magnitude of the rotational velocity is depicted by the thickness of the lines (thicker lines are higher velocity, thinner lines are lower velocity).
I'm told this is the correct way to produce turning motion, but my intuition (which is usually wrong) tells me that the two pictures should be reversed. My argument is as follows: For the picture on the left, the two rotors of higher velocity are spinning clockwise. If the motion of the rotors of greater velocity are clockwise, shouldn't the quadcopter also rotate clockwise? What am I missing here?