Recently I found these the two postcards shown in the image advertised in packs of North Korean (DPRK) postcards on Delcampe, including one pack from a dealer in China. I do not really know what they are or what they represent. I only bought them because they featured the Chollima.
They appear to be propaganda issues, one with a soldier riding the Chollima and the other with an image appears to be an angry worker with a ballistic missile taking off. I am hoping that some collectors of the DPRK issues can tell us the story behind these postcards.