Keith's update: As a reader notes NASA does not even know what "dark Side" means i.e. at least not consistently. The NASA press release for this image says "The series of test images shows the fully illuminated "dark side" of the moon that is never visible from Earth.
NASA itself is confused about this terminology: Common Moon Misconceptions, NASA: "Misconception: The same half of the Moon is in darkness all the time-i.e. that there is a dark side of the Moon. Reality: The Moon has no side that is constantly dark; the front and back are alternately lit as the Moon rotates. Far side is a more accurate term."