It is a form of courtesy that the guest follows the host during a state function. Bowing to the flag is practiced by some countries. From the picture, it looks a good 1.5 to 2m from PM Lee to the chancellor. Or perhaps the chancellor took some time during the bowing while PM Lee carried on walking, hence, the distance.
Who was the protocol officer for this function? Sure to be in hot soup!!!!!
Anyways, what happened next?