New photographs released by North Korean media show the country’s leader Kim Jong-un stripped to his undershirt on an inspection visit to a fish pickling factory, while officials remained in full uniform in the heatwave which has hit the Korean peninsula.

Not only can Mr Kim’s style of dress tell a story of the haves and have nots in North Korea, but the very timing of the visit shows how seriously Pyongyang is taking the heatwave in east Asia and the challenges facing the country’s food supply.

Mr Kim arrived at this week’s visit wearing a tailored grey jacket, straw hat and his trademark baggy trousers, a slight change from the “Mao jacket” favoured by his grandfather Kim Il-sung, the founder of North Korea whose style he has often copied.

It was the same story on a visit to a fish farm reported earlier this week – possibly on the same day, judging by the similar outfits worn by Mr Kim and Ms Ri – where he was stripped to his undershirt after he and officials were splashed by decidedly feisty catfish.

Pyongyang says barely anybody wears vinalon these days – the uniquely North Korean fibre that is made from an unlikely mixture of alcohol, coal and limestone – but Kim Jong-un ordered an increase in its production in his New Year’s speech, why may hint at a comeback for the notoriously stiff fabric which is part of the country’s national identity.