Translation:They are descending from a hole in the ceiling.
The word qung was originally defined as "hole in a musical instrument", but in 2012 the meaning was then expanded to a broader category of holes, including "a hole in the roof". The distinction between qung and QemjIq appears to be similar to that between "perforation" and "depression" (or you can think of a QemjIq as a continuous deformation of the surface, while a qung is a hole in the topological sense).
Text of the e-mail (sent to the KLI mailing list by 'ISqu' on 2012-01-26):
(4) "hole" (like a hole in the ground) is QemjIq. This can also be used for the hollow in a tree. qung, the word for "hole in a musical instrument," can't be used for a hole in the ground, but it could be used for a bullet hole or a hole in a shirt (including buttonholes, moth holes, accidental rips, etc.) or a hole in the roof. You can fill (teb) a QemjIq, but not a qung.