Sun Day means Kim il sung's Birthday in North Korea. Kim il sung is the first dictator of North Korea and he is Kiim Jung il's Father. As you know, North Koreans are severly suffering from hunger.
Now days, North Korean diplomats and traders are being called to require support of food and fund dollars. But Kim jung il ignored current situation, just pouring thousands of dollars to celebrate his dead father.
According to the News article, he has a plan to use this event to promote his successor Kim Jung eun. I think North Koreans are so poor, Because they have to pretend to be happy and to honor called their legend Kim il sung. if not, they will be executed at early date.