SARAH VINE: William and Kate are portraying themselves not just as Royals and parents, but sweethearts too

We open with trees and dappled sunlight. Then ferns, close-up in all their magical symmetry. A slow piano begins, setting the tone.

The camera shows the Princess of Wales in a simple white summer dress decorated with black broderie anglaise, behind the wheel of her car as she drives through country lanes.

“Now that summer is coming to an end,” she begins, “I can’t tell you what a relief it is to finally have completed my chemotherapy treatment…”

The lens lingers on her hand as it rests gently on the gearshift, the jewels on her ring finger glowing softly. It cuts to slow-motion walking, some standing by a tree, a close-up of those famously luscious locks, and then the footage morphs into a home-movie-style film. Prince William and the children, dressed in artfully mismatched weekend wear, are frolicking in the Norfolk sand dunes.

The princess lays her head on his shoulder as they play with each other’s hands, giggling as they lie on the sand with their arms intertwined.

“Is this a recording?” asks Prince George, his face zooming into the camera, his mother smiling softly to herself in the background. They play cards with Grandma and Grandpa Middleton. Later, the princess walks alone through a summer field, her fingers grazing the long grass, the evening sun burning into the lens, before a rising crescendo of piano and strings, faintly Celtic in tone, signals the climax of this charming royal tableau.

The voice-over is by the princess herself; and the rest – well, it’s pure silver screen. The moment in the field is unmistakably reminiscent of the opening shots of Ridley Scott’s Gladiator. Is there a subliminal message here?

Either way, as far as royal announcements go, it’s certainly a significant departure. Even the Duke and Duchess of Sussex have never managed to produce something quite as slick or emotionally charged.

It also stands in stark contrast to the King’s own approach. His Majesty has adopted a rather old-fashioned, stoic attitude to his own illness, continuing to make public appearances and – on the surface at least – seeming to embody that old Churchillian adage, KBO (Keep Buggering On). The Princess of Wales’ cancer journey, meanwhile, has been – on the surface at least – rather different.

Granted, we don’t know—and probably never will—the exact nature of her diagnosis. But whatever the physical effects, emotionally it seems to have hit her very hard—a “scary and unpredictable time,” as she puts it.

As is often the case when a serious illness strikes, it has prompted her to look deeply within herself, to ‘reflect and be grateful for the simple but important things in life, that so many of us often take for granted. Of simply loving and being loved’.

While the king has managed to keep his head above water by keeping things as normal as possible, the princess has almost completely withdrawn from public life. This film marks the beginning of her return.

There may be some royal observers who find it a bit over the top. There is certainly an Instagrammable quality to it, a visual sophistication that traditionalists may find a bit jarring.

But I think that’s a generational thing. The Prince and Princess of Wales are millennial royals. They grew up in a visual age, but also an age where expressing your feelings wasn’t as frowned upon as it was for King Charles and his mother, the late Queen Elizabeth.

There is also a strong sense that this is not just about the Waleses as a family, but about William and Kate as a couple. They don’t often indulge in PDAs – public displays of affection – but that doesn’t mean they don’t love each other very much.

Here we see a bit of that love expressed physically in a way that is as unexpected as it is unfamiliar. They present themselves not only as Royals, parents – but also as lovers.

It is also a silent but extremely effective refutation of the rumors that have been circulating, especially on social media, in recent years.

Would I have toned down the slow-motion quirkiness? Probably. But there’s no doubting the authenticity here, or the genuine intent – ​​and a genuine desire to connect with the audience on a human level, to thank the nation for its patience, and to show real gratitude for all the support.

But what I find most moving about this film is the way the Waleses have turned the Princess’s experience into something positive. This is in stark contrast to the Duke and Duchess of Sussex’s response to their own problems, which seem to have only led them down an increasingly negative path.

The truth is that we all face challenges in life, whether it be through illness, adversity or something else. The real test is what you learn from these experiences and where they take you.

It seems to me that despite everything (not just the cancer, but the terrible Windsor row), the princess is in a happy place. It is joyful to see.