A jail cell above a Tehran square

Tehran's municipality installed a billboard structure in Tajrish Square, in one of the upscale districts of the north of the capital, with a small prison cell built on top. Inside, a man in a dark suit, a red tie and a latex mask of President Donald Trump sits on a bed beside a toilet, rattles the bars and performs the Y.M.C.A. dance. Behind him, an electronic screen shows images of a deadly American attack on an Iranian wedding, under the message that failing to see the scene is a crime. Pro-government media reported that the setup is meant to run around the clock, seven days a week. Passersby have posed for selfies, laughed and insulted the figure, filming the scene on their phones.

What the campaign is meant to convey

The municipality said the installation is meant to remind Iranians of the need for justice. The campaign commemorates Iranian victims of the conflict and calls for those responsible to be punished. Iran accuses the United States of deliberately targeting civilian sites during the war, including a school and a wedding ceremony in the south of the country, and says the strikes killed dozens of children and women. Since the killing of Supreme Leader Ali Khamenei on the first day of the war, the Islamic republic has presented Trump as a criminal and kept vowing revenge. Iran's billboards have long mocked its opponents, and over the summer a billboard in Enghelab Square showed Trump lying in a graffitied coffin.

Stalled talks and a deadly war

The war reached new heights of provocation in Iranian messaging after the United States and Israel attacked Iran in February. Trump has posted images, usually generated using artificial intelligence, that mock Iran's clerical rulers or depict their annihilation by American firepower. Lego-style music videos by an anonymous group called Explosive Media have frequently gone viral, though analysts said they drew more interest abroad than inside Iran. Trump rejected an Iranian plan to reopen the Strait of Hormuz and halt hostilities, saying Tehran wanted a deal because it was losing. He later assured that the United States would not launch new attacks before the midterm elections on 3 November. At a rally he raised the possibility that Iran could strike Los Angeles or San Diego, then said his words had been misunderstood.

Public mood and what comes next

Tehran says it will not resume negotiations until Washington accepts conditions, including an end to hostilities, the lifting of the blockade of ports and the easing of oil sanctions. Iranian public opinion is deeply divided on the regime, especially after a brutal crackdown on nationwide protests in January. Even so, there is widespread anger toward the US president for launching a devastating war on Iran. Iranians who often walk past such imagery have stopped to look at this one, and international news agencies have published video of the masked actor gesturing to the crowd. Inside the cell the figure gestures and issues threats at passersby, while reactions in the square range from laughter to insults.