Rude gestures are rare on postage stamps, but Ukraine's most famous stamps have one. The video shows a soldier raising his middle finger to a Russian warship in reference to the confrontation on Snake Island on the first day of the large-scale invasion nearly three years ago.
The Russians demanded surrender but the Ukrainians refused, using unprintable language.
The warship in question, the cruiser Moskva, was sunk by the Ukrainians two days after the stamp was issued, and was sold out within a week of being put up for sale.
Such is the significance of the seal that was all that remained Granted to government delegations Representing Ukraine on the world stage.
Ihor Smelyansky, head of the Ukrainian postal company Ukrpushta, admits that the move was risky.
He told the BBC: “It was my decision. I said I don't care what other people think. I just think it's the right thing to do.” “I know this breaks all the (stamp study) rules and all the rules. But we're meant to break the rules.”
Ukrpushta often tests her designs on the public, and the results of such online polls tend to be highly political as well.
That's how the best-selling Ukraine stamp came to be, showing a Ukrainian tractor towing a captured Russian tank and including the popular wartime greeting: “Good evening, we're from Ukraine.”
Ukrposhta sold about eight million of these stamps.
Stamps featuring Ukraine The famous mine-sniffing shepherd dog Ukrpushta earned about $500,000 (£400,000): 80% of the money was spent on demining equipment, and the rest on animal shelters.
Another seal of A A mural left by the famous graffiti artist Banksy On a bomb-damaged building outside Kyiv, he helped fund 10 bomb shelters. This stamp bears another popular unprintable Ukrainian slogan, this time directed against Vladimir Putin.
A dose of humor was added to Ukrapushta stamps to maintain Ukrainian morale during the war with Russia, says Ihor Smelyansky.
“Humor has become a fighting force for the Ukrainians in this war,” he told the BBC. “Even in the most difficult circumstances you have to deal with it with a sense of humour. And that's what our stamps are about sometimes.”
Ukraine's approach to stamps by focusing on war is highly unusual, says Oscar Young, of UK stamp dealers and auctioneers Stanley Gibbons.
He told the BBC: “In general, stamps are artistic and polite, but to go out of style and be very rude, and put profanity and extreme gestures on stamps, is unique in these particular cases.”
He says it was the candid image used on the warship stamp that made the stamp so popular and caused such a stir when it was issued.
The distinctive character of Ukrainian stamps has made them popular with philatelists around the world.
Laura Bullivant from Gloucester, UK, thinks the other stamps look bland in comparison.
“I think they're similar to the Ukrainian thought process, they're just tough, they don't bend to anything that comes to their country,” she says.
“At a time of great anxiety and atrocity, they bring something to the game that no other country can.”