Commentary on the photo below is from one of our foremost Korea Hands. Although there is speculation on Jang Song-taek's absence, I think the members that were present is significant and I think the fact that this meeting is made public is important as noted in the comments below.
Clockwise from Supreme Commander Kim Jong-un is Kim Kye-kwan, First Vice-Foreign Minister; Kim Yong-il, Director of the Party’s International Department; Kim Won-hong, Director of the State Security Department; Choe Yong-hae, Director of the General Political Bureau (political officers within the KPA); Hyon Yong-chol, Chief of the KPA General Staff (NK version of the US JCS Chairman); Hong Sung-mu, a Party vice-director (which the ROK Govt assesses to be Vice-Director of the Munitions Industry Department which controls nuke and missile programs); and Pak To-chun, Party Secretary for Military Munitions (the man who got much of the credit for the recent missile launch).
Although KIS did some of this (not in a timely fashion), I do not recall Kim Jong-il ever staging this type of "national security" meeting and reporting it through KCNA so the whole world could see. KJI's ego would not have permitted this to be public. He always showed his national security concerns through "management by walking around" at base or exercise visits. This is an apparent message to back up its recent threats to the US and the ROK...and to make KJU look tough. The Bolshoi Ballet could not have choreographed this better.