This is a difficult one, Dani. There are so many different ways of looking at it.
Nobody would deny an activator to use a tent or "bivvy bag" on a summit, and it is customary to take advantage of any shelter that the summit offers. I have seen activation photographs where the station has been set up on a picnic table outside a summit cafe which serves skiers, which is acceptable but a bit uncomfortable for a purist. If the photograph shows the mountain refuge in question then it looks to be a sunstantial and well maintained structure, and this may well be uncomfortable to a purist but is not against the rules.
I would offer the thought that this should only be against the rules if the structure has power available, otherwise it should be seen in the same light as a (very) substantial tent.
What do others think?