It might have been better to keep posting in the other thread If there is no double exposure of someones net curtains (agreed that this is rather unlikely in the circumstances) then I'd say it looks like x-ray damage. One would expect effects from water-damage (freeze/thaw condensation) to be less regular, though I have only seen that from an extreme-rain accident where maybe more water was involved. Have the house moves been inter-country where the container or packages have been subject to a random-search?