Hallucinogenic Realm
What if Veronique's haunt is actually a sort of prepper bunker, a metal womb. Also the biomass of Gerry and Christina surrounds her, but she maybe has pushed it back to give her more room to breath. Either the bunker itself has sort of translucent walls and we see the womb beyond, or the womb is within a bunker culvert, maybe an actual bunker under the earth that is the physical locus of hallucination.