Kim Jong-un presided over solemn memorials to mark the second anniversary of his father's death on Monday. One particular snapshot can provide us with insight into the leadership in the wake of the recent brutal purge of his uncle, Chang Song-thaek, explains North Korea leadership specialist Michael Madden.

2013 status: He runs the secret police and is regarded as very powerful. He is likely to have played a key role in Chang Song-thaek’s demise. In 2012 he was in the second row, while in 2013 he has moved up to the front row.

2012/13 status: Visited Cuba in July 2013, shortly before missiles were discovered on a North Korean ship which had left Cuba and docked in Panama. He has since disappeared and was thought to have fallen from favour. However, in an image of Chang Song-thaek being removed from parliament, he can be seen sitting in front of Chang.

2012/13 status: In 2012 this was a powerful position. He has since been demoted and does not figure prominently in 2013 picture.

2012/13 status: Kim Jong-un's uncle was regarded as a powerful figure in 2012 and was seen by outside observers as the new leader's mentor. He was known to be a proponent of economic reform. By December 2013 Chang Song-thaek had been executed - accused of multiple crimes, including forming a power base and attempting to overthrow the state.

2012 status: He was powerful in 2012, but appears to have gained more favour over the last year.

2012 status: In charge of the scientists and researchers in North Korea’s weapons programme. He had pride of place in 2012 because they had launched a missile just five days earlier. He and a number of his staff were invited to commemorate the anniversary as a mark of favour. They did not feature in the 2013 image

2012 status: In December 2012 he had been leader for a year and was still surrounded by the men appointed to oversee his transition to the leadership.

2012 status: In December 2012 she was in her first year as the first lady of North Korea and had made a handful of public appearances by that time. This was one of the most important.

2012 status: In 2012 she was in a position of great power as the younger sister of Kim Jong-il whose death they were commemorating. In 2013 she was absent following her husband Chang Song-thaek's execution.

2013 status: Had a prominent role in six-party talks over the country's nulear programme. Was though to be close to Kim Jong-il and is clearly still a powerful force. Moved up a row from 2012.

2013 status: Powerful and a member of the Kim family by marriage. He has moved up a row from 2012.

2013 status: Another one of the so-called gang of seven. A remnant of the old era and thought to be a reformer. In 2013 he was not visible. Analysts think that because he is ageing he may be permitted to shed roles and responsibility.

2013 status: He is one of the old guard who has not been purged. One of the so-called gang of seven who walked with the hearse of Kim Jong-il in 2011. He features in the 2012 photograph.

2013 status: Was not prominent in the 2012 picture, but has been promoted and is now in a position of favour and power. He is thought to have a similar reformist outlook to Chang Song-thaek and is believed to have visited South Korea to survey its economic development.

2013 status: On the face of it, he appears to have tightened control after his purge, but some analysts see it as a sign of weakness.

2013 status: Considered extremely powerful. He has seen his influence increase over the last year.

2013 status: Promoted in August. Is not visible in the 2012 picture. He is the fourth person to hold this job in two years, but his position is currently regarded as stable.

2013 status: Was not prominent last year. He has received a recent promotion and his status is regarded as solid.

2013 status: Always present at public events. He is a crucial figure as he is charge of the daily management of production of weapons and WMDs. In 2012 he was standing right behind Kim Jong-un.

2013 status: A member of the so-called gang of seven who walked with Kim Jong-il’s hearse in 2011. One of the few survivors of that group, he was moved to another post and now runs the citizen militias.

Early on 17 December, North Korea's elite paid homage at the Kumsusan mausoleum where the embalmed bodies of former leader Kim Jong-il and his father, the founder of the nation, Kim Il-sung lie.

They did exactly the same a year ago - but it was a different group of people. Comparing the line-up this year with the photograph taken last year can give us some insight into the power play in this secretive nation.

Conclusions are difficult to reach because the regime is both opaque and unpredictable, but there are possible clues about the future direction of Kim Jong-un and the men who surround him.

The images may look virtually identical but there are many hidden signs of subtle but potentially significant changes among North Korea's top leaders.

Power to the right?

There are several new faces in the front row and more military uniforms. The military and security staff are on Kim Jong-un's right and the party people are on the left. This represents a reversal from last year.

Some defector sources say that if you are on the right you are in a more valued position than if you are on the left. It is hard to say how true that is, but there is definitely an argument current among some that those on the Supreme Leader's right wield greater power.

The most notable absence is what has dominated headlines - which is that of Chang Song-thaek, recently executed in an unprecedented public purge.

Chang's widow Kim Kyong-hui is also missing from the picture, but few expected her to be present and it is difficult to know what to read into this. Some may see it as a sign she is out of favour but others have suggested that she may have even played a role in the purge.

People that Chang had social ties with and associates with a similar reformist outlook were present - one is the current prime minister, Pak Pong-ju. He seems to have come to the fore in the last year and occupies a prominent position in the line-up.

Two new names in 2013 stand out: General Ri Yong-kil and Defence Minister Jang Jong-nam - powerful figures to watch.

Ruthless rising star

China is the other silent presence in this picture. The men in civilian suits standing on the right of the picture - Kim Ki-nam and Choe Tae-bok - are all figures with ties in China and interests in foreign relations. These were people present in 2012 and so their inclusion projects a message of continuity - even if just cosmetic.

Another interesting figure obscured on the left is General Kim Won-hong but he is not to be overlooked. He runs the secret police, thought to be very powerful and whose star is rapidly rising.

He is likely to have played a key role in Chang Song-thaek's demise. In 2012 he was in the second row - he has now moved up to the front row. We may well see more of him.

Three members of the so-called gang of seven - the old guard who accompanied the hearse of Kim Jong-il and were thought to be appointed to oversee the transition of power - are also visible at the front.

Michael Madden runs the North Korea leadership watch website.