 The meeting room is containment unit S167-001006, which is the skull of a stillborn cryptomorphia gigantus. The holdout space inside the skull cavity is a prototypical Vegas room, a place where what happens stays. People go in, they come out, their memories are sieved out of the universe as they leave, and they remember nothing. The skull was acquired in the 90s. The information suppression effect is a byproduct of the species natural antimimetic camouflage, a phenomenon which rendered the colossally tall creatures somehow nearly impossible to observe in the wild. It's a phenomenon Dr. Bartholomew Hughes and his team spend years figuring out how to replicate. They've got it now.