One of the enduring images of last week was the headline photograph of Prime Minister David Cameron, President Obama and the Danish Prime Minister (whose name escapes me) grinning inanely as the Danish PM took a picture (commonly referred to as a “selfie”) of the three of them on her mobile phone.

By itself there’s nothing wrong with that, just a bit of harmless fun in an often over-serious world – except that this was at a memorial service to the late Nelson Mandela whose funeral, at that time, had yet to take place.

For some reason, I cast my mind back to bygone images of world leaders pictured together and I settled on the famous photograph of the three allied leaders, Franklin D. Roosevelt, Joseph Stalin and Winston Churchill taken at the Yalta summit in the latter days of the Second World War.

I wondered, had the technology been present at that time, whether any of those men would have taken a selfie at their meeting. I think we know the answer.

In this blog I have, on more than one occasion, referred to modern leaders as “political pygmies” in comparison to their forbears. After the events of last week, there can no longer be any doubt.