About many people who went through NDE, a common experience is being in a white room. After going through many testimonies, my guess is that a hospital room is white, and people with near deaths are usually sent to hospitals, thus they mistook it as an afterlife trip and a meeting with the dwellers on the other side.
Actually, this may mean that there is no afterlife or reincarnation after all, and that human body and soul end when life ends. This means our presence as an observer vanishes, which is frightening. That is why death is so scary, because it may really be the end of our existence in body and soul. Ashes to Ashes.