What I don't like about this dream is Nancy Barrett's high-pitched puppet voice. Even my dog reacted when the puppet started singing "Happy Birthday."
I was amazed at how solidly she hit the high note in "Happy Birthday".
Nice acting by David Selby in the dream; Quentin was much more isolated and apart emotionally than he was in 1897.
I did my best to get a good look at Roger's face, because Edward's face seems as though all the features are squashed together in the middle of the face. It didn't seem that way with Roger. Louis Edmonds's nose seemed much longer, thinner, and haughtier on Roger than it does on Edward.
As for where the dream came from, I think it was the I Ching helping Barnabas out, in the same way that I believe the I Ching helped him previously by giving Magda the vision in the crystal ball that caused her to send Sandor to the mausoleum at the beginning of Barnabas's visit to 1897. (I think I've mentioned before that I think the I Ching had a soft spot for Barnabas, and a good thing, too; he would never have made it through 1897 on his own.) The dream clearly was not a representation of an actual event in 1969, because, as others have noted, the people in the dream (including Quentin's ghost) weren't really like the 1969 characters. Also, as alwaysdavid noted, Josette's portrait was in the wrong place. I think, however, that I saw in the dream drawing room a piece of furniture that (significantly, as it turns out - was the I Ching providing a helpful reminder?) is not in the Old House drawing room in 1897.