Alternatively Pyongyang, in referring to a "higher level" test, may simply be aiming to test a larger device, substantially bigger than the 1 and 2 kiloton tests of 2006 and 2009.
By aiming to have one platform run across multiple device footprints, they can leverage the support and tools from the desktop version of Ubuntu and put them into a mobile device running the same code, but with a mobile UI layer on the top.