The fresh encounter with his former sweetheart was interpreted as evidence that the youngest Kim was shaking off his father's influence.
Whether the woman photographed with the young leader really was the singing star has never been been clarified. A fortnight later, when Kim was photographed with another young woman on his arm at the opening of a Pyongyang amusement park, North Korea's official media pointedly identified her as his wife, Comrade Ri Sol-ju - a woman who had performed with the same group as Hyon Song-wol.
This terse announcement was a revolution in North Korean terms, where the private lives of the rulers have been kept a strict secret.
Hyon Song-wol's patriotic hits included Footsteps of Soldiers, I Love Pyongyang, She is a Discharged Soldier, We Are Troops of the Party and Excellent Horse-like Lady.
Why she and her fellow musicians were reduced to selling videos of themselves having sex, and why this severely proscribed activity was punished in such a cruel and public fashion, remains a mystery.
Chosun Ilbo, the respected South Korean daily with sales of more two million, reported that Hyon Song-wol and her colleagues had been arrested on August 17 for breaking pornography laws. Their public execution took place three days later, with other members of North Korea's most famous pop groups forced to watch before being dispatched to prison camps, from which few prisoners return.
The severity of the punishment indicates there is a political dimension to the case, according to one Japanese authority.
Professor Toshimitsu Shigemura of Waseda University in Tokyo told the Daily Telegraph: "If these people had only made pornographic videos, then it is simply not believable that their punishment was execution.
"They could have been made to disappear into the prison system instead."
Such a hideous fate could only be explained if the singer and her comrades had been identified with a rival power faction in Pyongyang, the professor said.
An alternative explanation was that Hyon Song-wol, so publicly identified with Kim Jong-un, had attracted the jealous ire of Kim's wife - who once belonged to the same singing group.
- Independent