Take, for example, the photograph (it’s graphic) published on the front page of Monday’s Australian showing a seven-year-old boy hoisting by the hair a severed head. The now-viral photo reportedly originated on the Twitter feed of the boy’s father, Khaled Sharrouf, a Sydney jihadist fighting with the Islamic State, with the caption, “Thats [sic] my boy!” The head belonged to a Syrian soldier; it now belongs to the citizens of Raqqa in north-central Syria where the Islamic State displays dead Syrian soldiers on the sidewalks, perching their heads atop their bodies or mounting them on poles.

Whatever father/son bonding opportunities they may provide, the Islamic State’s tactics — mass execution, beheading, crucifixion (graphic content at all three) — are being practiced with an alarming enthusiasm. How do we know? Because the jihadists themselves post the evidence: cell-phone videos and Twitter pics uploaded by the Islamic State with the same sort of abandon with which tourists photograph their desserts — not Matthew Brady daguerreotypes or Eddie Adams Pulitzer-winning frames, not even “photojournalism”: snapshot propaganda.

The precedent is not Robert Capa; it’s 3-Babiez. Albeit with variations, the Islamic State is perfecting what might be called the “terror selfie”: a quick click that, like Mexican-cartel propaganda, aims to frighten the audience, but also to flatter the photographer. Flaunting unlikely threats (“We will raise the flag of Allah in the White House”) and trophies (heads and torsos), the Islamic State’s self-made media is its way of flashing its gang signs over the bodies of its victims.