Image copyright Rodong Sinmun Image caption State newspaper Rodong Sinmun shows Kim's wife Ri Sol-ju dutifully holding his jacket

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.

The photos, which filled the first two pages of state newspaper Rodong Sinmun, show the Supreme Leader inspecting the Kumsanpho fish pickling plant alongside his wife Ri Sol-ju.

But as with most things North Korean, it's what's not been said by the distinctly "fishy" news release carefully-prepared by Pyongyang's Propaganda and Agitation Department which raises eyebrows.

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.

Image copyright KCNA Image caption Power stance: Kim Jong-un converses with officials on the thorny subject of fish pickling as First Lady Ri Sol-ju looks on

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.

With temperatures in North Korea earlier this week nudging 37.8C (100F), he soon ditched the jacket, carrying on his visit in his undershirt tucked into his grey slacks.

But while the Supreme Leader cooled down in more casual attire, the rest of his entourage - including senior military officers, party officials and factory bosses - remained sweltering in their uniforms.

First lady Ri Sol-ju can be seen, dutifully carrying her husband's jacket over her arm.

Image copyright KCNA Image caption Everybody got a soaking at Samchon catfish farm

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.

While Mr Kim often sports tailored but utilitarian outfits, many workers in the country wear clothes made from synthetic fibres.

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.

It's also used for fishing nets, which underlines the country's need to diversify its food sources as climate change delivers unpredictable harvests upon an already food-deficient economy.

Image copyright KCNA Image caption Mr Kim's visit to a lubrication products factory in 2014 highlighted the differences between the country's workers and ruling cadres

Two inspection trips in less than a week to fish factories could also illustrate how seriously North Korea is taking the heatwave.

The country has already said that it is suffering drought conditions due to prolonged unusually high temperatures, and that's likely to hit agriculture hard in a country where it was reported last year that 70% of the population relies on food aid.

So visits to sites illustrating the government's determination to at least look like it is self sufficient in food play an important part of state propaganda, promoting alternatives such as fish and mushrooms.

In fact, the earlier trip to Samchon catfish farm showed nursery tanks writhing with fish, with KCNA news agency saying that the facility ran at 10 times capacity last year.

Perhaps pressing home the urgency of the national food supply, Mr Kim was reported as ordering the farm to do the same again this year "without fail".

Image copyright KCNA Image caption Tanks squirming with fish, Kim Jong-un orders record production from factory officials

North Korea's tightly controlled media goes to great lengths to ensure that only Party-approved messages reach the general population.

These messages ensure that the Kim family is promoted almost constantly, along with state military-first policies that promote national self-sufficiency.

Pyongyang, either by accident or design, sometimes can't help leaving hidden messages in its news reports.

Last year, North Korea "accidentally" revealed details of two previously unknown ballistic missile types during a Kim Jong-un inspection visit to a defence academy.

And a series of visits last month where Mr Kim displayed his anger at local officials, including a power station still unfinished after 17 years, hinted at a coming crackdown on those who think they have a job for life or are tempted by corruption.

While the Supreme Leader may draw global headlines by stripping to his vest, it's really what goes on in the background that counts.

BBC Monitoring reports and analyses news from TV, radio, web and print media around the world. You can follow BBC Monitoring on Twitter and Facebook.