As we continue to mourn the helpless victims of the terrorist attack at Holey Artisan Bakery in Gulshan, I keep looking at the"official" photographs of the five militants, who stunned an entire nation with an unprecedented carnage on July 1.First released by Amaq, Islamic State's news agency, and then the SITE Intelligence Group, these photos present five young men, as if they were posing for an exotic advertisement or school yearbook.

Yes, by now we know who they were, where they went to school, who they were friends with, their Facebook profiles, etc. But, still, questions remain. Who were they, really, in their final days? Why do their photos show them donning identical black punjabis and iconic red-and-white kaffiyehs? Why did they need to pose in front of an ominous ISIS banner and hold identical automatic weapons with identical body language? Most important, why did they need to present calm, resplendent, and next-door-boy faces, even though they were zero-empathy killing machines? What is this visual story of extreme opposites?

Highly choreographed representations of ISIS killers and their gory acts are at the heart of the fanatic group's propaganda campaign. The goal seems numbingly simple: how to synthesise polar opposites—very normal-looking people carrying out extreme violent acts.

The photographic narrative of the Gulshan attackers is paradigmatic and encapsulates the ideology that drives the murderous ISIS movement: The banality of cruelty. That is, cruelty has to be exhibited with such nonchalance that it would seem normal and routine. Cruelty is designed to be seen not as a mutilation of bodies but as an act of punishment, meted out by obedient foot soldiers, to those who didn't conform to one macabre vision.The act of cruelty is even bureaucratised: kill with a sword or machete, dismember the body, shed a lot of blood, take pictures of the ghastly scene, and upload them on the social media for the world to see and fear. Cruelty must be a triumphantly simple enterprise, yet its effect must be sensational.

This is perhaps the next phase of what the political theorist Hannah Arendt called "the banality of evil" - Arendt's oft-repeated argument concerning the trial of Adolf Eichmann that the Nazi henchman's genocidal campaign was less about the result of a radical ideology and more about the reflection of a society's everyday practices, as simple as meeting one's daily obligations. The evil person doesn't see his heinous act as evil but rather as a simple occasion to fulfil his duties. When an evil action becomes banal, there is no moral confusion. Such a condition helps make the most brutal violence appear as normal as daily chores. Zero empathy becomes gloriously possible.

Arendt's insight serves to explain what the gun-toting and machete-wielding militants at Holey Artisan Bakery sought to accomplish. As in other cases, the Islamic State-orchestrated portraits of the Dhaka killers were designed to debunk the myth that terrorists look repugnant, hateful, and sinister. Rather, the visual argument was that these were homeboys, who just dutifully carried out their routine work. They were asked to play the role of an expanding caliphate's triumphant, happy soldiers. And, they were expected to execute a linear policy of exclusion and extermination that couldn't be disturbed with any ethical qualms.

It didn't matter if the "sinners" included Simona Monti, a 33-year-old pregnant Italian woman; or Faraaz Hossain, 20, who refused to leave without his female friends; or Hiroshi Tanaka, an 80-year-old Japanese man, who came to Bangladesh to help alleviate traffic congestion. Cruelty had to be tranquil, or else, their extermination strategy warranted too much rationalisation and moral inquiry. Cruelty had to be exhibited with total banality.

Thus, for the young terrorists, who stormed into Holey Artisan Bakery, butchering innocent restaurant patrons was ultimately not about killing people. For them, it was about doing the needful to create a religious utopia, populated only by their ilk. In their minds, their act was not evil at all. It was, for them, a self-righteous war against the perceived enemies of Islam. At the end of their bloody operation, the banality of their cruelty was matched by an equally banal goodbye: "See you in heaven. Take care."

In all of this, the young killing brigade's grisly work was also designed to be a sensational spectacle, an effective visual warning to those who didn't subscribe to their perverse interpretation of faith. The terrorists are believed to have nonchalantly uploaded the gruesome images of mutilated bodies, as if they were harmless selfies for family and friends to enjoy. These young militants were most likely trained to display a corporate efficiency in packaging cruelty.

The Gulshan attack was orchestrated by a global terror network that feeds off local grievances and tensions. Local discontents and alienations morph into an allegiance that is global. Terrorism's local-global debate is moot, especially when a violent group is unleashing atrocities all around the world with the systemic callousness of a neoliberal company.

The writer teaches in Washington, DC, and is the author of Oculus: A Decade of Insights into Bangladeshi Affairs (2012).