A father shares a kiss with his adult son. It was an image of simple tenderness, but which, in its own way, was something of a mould-breaker. Prince Harry welcomed his father with an unabashed snog at the Chelsea Flower Show this week, an expression of unscripted and genuine warmth that was unusual on several counts.
We are led to believe that exchanges within the Royal Family are conducted in a rather more formal way, but, inspired by Harry's example, even Prince Charles and the Duke Edinburgh greeted each other with a kind of embrace. Notwithstanding the fact that they both had the expressions of men who had sucked on a bag full of lemons, this represented a departure for the senior Royals, who are not known to wear their feelings so lightly.
It is not that long since Prince Philip expressed his emotion in the immediate aftermath of Princess Diana's death by casually tossing a bouquet of flowers among the floral tributes on the pavement outside Buckingham Palace.
We know that relations between he and Charles have often been strained, and that a picture has been built up of the Duke as a remote and disciplinarian father. Yet here they were, if not actually kissing then getting pretty close to it. These were images that portrayed a very different image of the House of Windsor, and revealed the potentially transformative power of the younger Royals.
For an emotionally constipated nation - most vividly represented down the centuries by our ruling classes - the sight of men kissing in public, whether they are blood relatives or not, is still unusual. And when they are members of the Royal Family, even more so. Our upper lips are meant to be stiff, not puckered. Leave that kind of thing to those bloody Froggies, you can almost hear the Duke of Edinburgh say.
But we should welcome this development. Why shouldn't men kiss each other by way of saying hello? I do it all the time. Among fellow metropolitan types it seems perfectly natural. Yet I would no sooner kiss one of my golf partners at my club in rural Oxfordshire, or one of my football mates, than I'd greet the Archbishop of Canterbury with a fist pump. For them, a manly handshake will suffice, thank you very much.
Why should that be? Are they not up for it, or is it me? Young people, however, don't have the same inhibitions. The modern propensity for over-sharing may not be to everyone's taste, but there is a lot that we of older generations can learn from young people's willingness to express their emotions volubly and demonstrably.
Prince Harry, as a totem of a certain type of outgoing youngster - and by that I don't just mean he goes out a lot - is perfectly at ease with kissing his dad, even though they are almost certainly the first Royal father-and-son to do so in public. The fact that it appeared organic is to their credit, and does more than a thousand walkabouts to soften the image of the Royals. It is also one of those rare examples of the Windsors giving a lead in the emotional mores of the nation.