Kevin Costner to Oliver Stone upon first reading the line "We're through the looking glass here, people" in the "JFK" screenplay

The fuck does this mean. "Looking glass?" Those aren't--that's not a thing people use--or say. The fuck is--looking glass? I've never--I don't know what that is.

And through--the glass? Through it? How is that--are we talking ghosts through solid objects or just like--opening a window and walking--but like, again, looking glass, I don't--.

Is the glass looking? Through the looking glass? Through the glass which is looking? Like a personification thing or--did you mean looking glasses? Looking glasses? But still, through the glasses, I don't--

The through, I think it's the through that's throwing me mostly. Through--glass--but looking glass too, that's--did you mean--"we're looking through the glass here, people." Now that--that makes sense to me. Like we're here. Looking through glass. There's no movement, not going--through anything, but I'm still not clear why--why that was there at all. But like we're here. And the glass is there. Just--glass. And we're--looking through, at other people. "We're looking through the glass--at people, here--people." See that makes much more sense to me.