This would seem to imply something we would recognize as tech, namely a portal or gate of some kind. it seems to only be visible at the entry point, rather than the exit point, given the differences in arrival. perhaps a focus point of some kind?
"...I discovered a light appearing in my room, which continued to increase until the room was lighter than at noonday, when immediately a personage appeared at my bedside, standing in the air, for his feet did not touch the floor...."
"After this communication, I saw the light in the room begin to gather immediately around the person of him who had been speaking to me, and it continued to do so, until the room was again left dark, except just around him, when instantly I saw, as it were, a conduit open right up into heaven, and he ascended until he entirely disappeared, and the room was left as it had been before this heavenly light had made its appearance."