In what ways does Chongjin differ from Pyongyang, according to Demick?

According to Demick, Pyongyang receives much more of the regime's attention than Chongjin and thus feels more prosperous than the northern, isolated, industrial smaller town. Pyongyang acts as the regime's symbol of power, the image it shows to its own population as well as to foreigners to proclaim success through Communist social structuring. However, Demick is careful to show how the reality of life in North Korea is very different: since only the most elite North Koreans are given permission to live in Pyongyang, the rest of the country, with Chongjin as an example, often suffers for lack of political attention. Chongjin is thus poorer and physically cut off from the rest of the nation, leading to much more illegal activity, smuggling, and defection taking place.

In what ways does Mrs. Song deserve the label of 'true believer' in the North Korean regime?