A quick show of hands please: Who thinks a 38-year-old is still young?
It's a question I've been pondering after spending too long staring at new pictures released of the Queen and her extended family. Taken at Windsor Castle, they mark the end of William and Kate, Duke and Duchess of Cambridge's three-day "thank the nation" royal train trip.
These shots have gotten royal watchers in a lather because they are the first images of the 94-year-old monarch with her family since before the Covid pandemic began.
Given that each royal house will be spending the festive season in their own vast stately homes, this is the closest the world will get to an injection of jolly Windsor family festive togetherness for quite some time. (Maybe the fact that Philip wasn't in the photo can be put down to the fact they simply couldn't find him in the castle's 1000-odd rooms …)
As far as official royal snaps go, it is pretty bland. No touching, lots of rictus smiles, smart coats and a sort of best-behaviour rigidity that brings to mind school photo day.
That is until you realise this about the shot: This is it.
After the Prince Andrew debacle and in the wake of Megxit, this is the royal family now and they are a pale, stale and ageing bunch. These are the only senior HRHs left and it is their job to ensure that the monarchy endures in the 21st century. (The Queen's cousins – Princess Alexandra, the Duke of Kent and the Duke and Duchess of Gloucester – are also official working members of the royal family but does anyone really care?)
Forget thriving – they just need to survive.
And based on these new pics – so totally lacking in any sort of dynamism, so lifeless and bland – would suggest it's going to be one hell of an uphill battle, both practically and image-wise.
Currently, the average age of a working HRH is just under 68, that is two years beyond the retirement age in Britain. At 38, William and Kate are the representative young guns in the royal battalion.
When Harry and Meghan, Duke and Duchess of Sussex strode out of Westminster Abbey in early March this year to begin their new celebrity-adjacent lives in the US, gone with them went the royal family's most electrifying "hire" since Lady Diana Spencer first cast her famous doe-eyes towards the Prince of Wales.
The then Meghan Markle, actress, blogger and activist, brought with her an innate vivifying force that energised the royal family's brand. By lending her youthful verve and California cool to the house of Windsor she made the very notion of a hereditary monarchy seem not only interesting but relevant to younger generations.
It was an image refresh for the palace the likes of which they would never have managed to pull off on their own and the arrival of the Duchess of Sussex on the Buckingham Palace balcony was a branding coup so exquisite it would make both Saatchis weep with joy.
And now? The thrill is gone and in the vacuum their exit created, the inherent dullness of the remaining royal "troops" has become excruciatingly obvious.
This situation has been dramatically exacerbated by the pandemic. Gone this year have been the glamorous tours, the state dinners and the diplomatic receptions which would have allowed the Queen and Kate to pile on priceless diamonds, rubies, sapphires and emeralds and create a bit of that quintessential royal star dust.
Without the pomp, without all the frippery and the decadence and the gilt-edged everything; without the vast military displays and the show stopping moments of regal hauteur and the trumpets and the liveried footman, the house of Windsor has been stripped back and revealed to be just a bunch of ageing aristocrats.
The magic is gone. And that is a very dangerous place for the palace to be.
This is all even worse news for William and Kate because it will largely fall on their Marks and Spencer-clad shoulders to have to try and find a way to fix this looming disaster and to try and revive some of the dazzle.
Prince Charles might have long been a proponent of a thriftier, slimmed down version of the monarchy which has meant William's cousins Princess Beatrice and Princess Eugenie essentially shunted out of the picture and shut-out of official royal life but the wisdom of that model looks increasingly shaky.
The current working members of the royal family carry out more than 2000 engagements each year and hold 2862 official patronages. In 10 years from now, when Charles and Camilla are both in their 80s (and he will most likely be on the throne) the burden to meet this workload will fall to only four people – the Cambridges and Sophie and Edward.
Kate might have come in for plenty of lumps from the press for her alleged laziness in the early years of her marriage but as fate would have it, she is now facing decades of arduous service.
The bigger consequence of this ageing, royal labour pool is that it is terrible for their brand.
The photos taken this week at Windsor practically reek of stolid dependability which is an admirable quality when you are running an institution with a millennium-long history and you're all about longevity. But it is also very very dreary.
That matters because along with all that duty and responsibility, the royal family also needs to cultivate and hold public attention. For them as an institution to survive, we the people of the Commonwealth and the UK need to want them to remain in their palaces and for that we need to have some level of interest in them.
One of the few things that the most recent season of The Crown got right was the unparalleled, unprecedented reaction which Diana, Princess of Wales provoked wherever she went in the world. When she married Charles, she charmed, dazzled and enthralled the public and in turn the world became deeply invested in the royal family.
We cared about them.
So let me ask you: How much do Brits, and we the Commonwealth, care about the HRH's in the Windsor pictures from this week?
I'd wager that the biggest threat to the monarchy isn't some vast republican wave but a far more insidious, creeping passivity and indifference to the lot of them.
The palace needs the public to buy into the concept of a monarchy, which is why any growing disinterest is so dangerous for them.
And it's here that things get particularly rough for Kate, because it is going to fall to her and William to revive our flagging interest in the royal family, a challenge that is going to only get that much steeper when the Queen, who is widely beloved, passes away and King Charles III takes the throne.
She could also face the prospect of potentially having to put three children "to work" much sooner than she might like. Royal kids are normally very gradually introduced to working royal life, slowly building up their own solo engagements. William didn't undertake his first independent official outing until he was 23, a luxury that his son Prince George may not enjoy.
To shore up public support for the royal family, they will need all hands on the royal deck and the palace will have to deploy their most beguiling and adorable assets, namely, the Cambridge Three.
For Kate, who has from day one tried to instil as much normality into her family's life as possible, that would surely not be a thrilling prospect.
The 38-year-old has barely put a foot wrong since she joined the royal family nearly a decade ago but sometimes I wonder if the greatest legacy of this era will be that, inadvertently, the stories of both Kate and Meghan will quash, once and for all, any lingering fairytale notions of what being a princess (or duchess) is about.
Just ask the royal women left standing in the wintry cold for a photo this week.