With one puff of a cigarette, a woman in Canada became a global symbol of defiance against Iran's bloody crackdown on dissent — and the world saw the flame.

A video that has gone viral in recent days shows the woman — who described herself as an Iranian refugee — snapping open a lighter and setting the flame to a photo she holds. It ignites, illuminating the visage of Ayatollah Ali Khamenei, Iran's highest cleric. Then the woman dips a cigarette into the glow, takes a quick drag — and lets what remains of the image fall to the pavement.