Those aren’t ghosts — those are LCD projectors showing World War II operations. Ireally couldn’t make out what they were doing, but I don't think they were World War II-era films, I think they shot actors in period costumes and had them walk around. The attempt was to give some feel for the headquarters tunnel and what it must have felt like, but it didn't really work for me. Many different departments were in this tunnel, like logistics, meterology and combined operations. They have a lack of information about where each department was located and how many people worked in this tunnel. But the offices were very small - one office was between each of the black dots on the wall. Those are anchors for the partitions between each department. Right-click and choose "view image" to enlarge.