Kosher? Not so much, but Lennon opted not to say so. This was a place where entire floors could appear overnight, where a huge, heavy statue could appear to stand up and somehow be making odd noises, where they could be transported to another location with no one aware or having any idea how they'd gotten there. Anything could happen.
He turned and greeted Jack with a nod and a distracted smile and listened to what Daniel was saying. "Like he was behind the mirror somehow?" he asked. That was what it sounded like. Could it have been some kind of projection? Somehow he didn't feel like Daniel had dreamed it and he couldn't have explained why. Maybe because things were sincerely fucked up around here.