The image posted in this post was taken on 30th Tir, an uprising in support of Mossadeq’s bid to remove from the control of the Shah the appointment of the War Minister and thus the control of the military.
[Mossadeq] instigated a confrontation with the shah by asserting that he, as prime minister, had the constitutional authority to appoint the war minister as well as other members of the cabinet. This was the first time that royal control of the military had been seriously threatened. When the shah resisted, Mossadeq took his cause directly to the public. Ina radio broadcast, he argued that he needed supervision over the armed forces to prevent nefarious forces from plotting to undo oil nationalization. The public promptly poured into the streets, and after three days of general strikes and bloodshed, forced the shah to back down. The crisis became known as 30th Tir (July 21). [Abrahamian, E., A History of Modern Iran (Cambridge: Cambridge University Press, 2010), p 117]