The man belongs to a country originally shattered by an Anglo British coup, that went through a massively destructive war against an Iraq supported by the US (in which Marandi himself fought and survived two chemical weapons attacks: the chemicals btw supplied by the west), that has been suffering grievously from economic sanctions for years and has been the focus of all kinds of mad accusations and subject to endless threats ( see Trumps latest lunatic outburst for example) not least from Israel which has been trying for many years likewise to pull the US into a full scale war against it and which has also seen numerous arbritary terrorist assassinations of it's top military and political figures by both Israel and the US.
And here he is...an educated professor (UK educated: Birmingham Uni. btw) who knows his geopolitics (he ran the North American Studies program at the University of Tehran) having to listen and to take seriously this quite bizarrely propagandised summary of events by a western " journalist" which in fact attempts to depict the exact opposite of what we can see in the actual footage with our own eyes. He's an educated & very well informed individual being treated with contempt: why would he take this childish nonsense seriously without grinning?