Apparently, no Domain Name Service is required in the DPRK. Instead, all these sites are listed by their private IP addresses on the country's private intranet. Martyn Williams, a senior correspondent for IDG News Service, provided an analysis of the poster in his North Korea Tech blog, noting that while DNS appears to be in use within North Korea ("The North Korean Samjiyon tablet PC had several default bookmarks in its Web browser that used domain names," Williams writes) its availability is likely limited. In most photos of North Koreans using computers in schools and libraries, the addresses in browser windows use numeric IP addresses. (See Williams' post for a full translation of the table on the poster).
This might be because existing DNS servers in North Korea don't support the Unicode domain names that would allow users to type them in Korean. "If you don't have have much experience with the roman alphabet and a computer keyboard, typing a short string of numbers is probably easier," Williams noted.