Especially striking, besides all the marching and running around with giant ribbons, were what might be called the human cartoons. This is how you do it. Fill one side of a stadium with several thousand schoolchildren - maybe 60,000 for major events. Give each a wad of big cards in different colors. Drill them to perfection on what to flash when.
All countries have their youngsters parade in stadiums now and then.
But as you'd expect, North Korea has taken this to extremes - and then some. Like a lot else in North Korea, there's nothing originally Korean about it. The practice began in 1947, even before the DPRK was founded as a state. There was Soviet influence, plus a Czech strand. Those days are gone, but on home turf the displays are still going strong.