The line between subjective truth and propaganda is as old as war, politics and religion, but what’s disquieting today is the velocity at which it moves, and how impossible it is to shove the genie back into the bottle. What are we to believe? Social media have given a populist, liberating edge to what we see, but how do we discern fiction from truth? And will images resonate in the eye long enough to meaningfully shape a generation with an insatiable fascination for the next swipe and click.