Those unlikely North Korean monarchists

I've always been slightly confused by the North Korean government's fondness for royalty. The Lonely Planet guide to Korea (1997 edition, p400) notes in its section on things to buy in North Korea:

You might enjoy the stamps featuring North Korea's version of the space shuttle, but even more bizarre are the stamps proudly displaying the British royal family. Just why Charles and Diana are more popular in North Korea than in the UK awaits some scholarly resarch.

I suppose hereditary leaders are not exactly a foreign concept in the North.