DPRK soldiers can't be taller than Kim. Worried that some soldiers will try to challenge him physically, long ago the Kim dynasty made it illegal to be taller than the Great Leader. As a result the country has worked to keep the populace at or under 160cm.
Some allowance is made for a few centimeters above the limit by using hats to hide their height while the Kim family hairstyle adds a few. This way ensures that Kim stands out in every picture, this confirming the nature by stature of the Great Leader.