Your first question is answered by the picture itself, there is one more yet before parade started and lights out with reflection of fireworks on the wet pavement at the square nicely reflecting.
CCTV posted only two images of the parade, this one is only noteworthy as it shows new MLRS(?).
If it is MLRS then it looks to me one that launches thermobaric rockets, unless something else.
This nation carried on through the civil, cold war, deadly embargo and stood firm. After 2020 seems that they are going well in material quality and quantity. My respects to the DPRK. Keep on keeping it true with your brush honorable Korean people