Revealing mistake: When Ariadne is pulling the two huge mirrors close together underneath the bridge with Cobb, watch her when she is closing the second mirror. She steps over something even though there is nothing present for her to step over. There must have been a green screen frame there for her to step over.
Inception (2010)
Plot summary
Directed by: Christopher Nolan
Starring: Michael Caine, Joseph Gordon-Levitt, Leonardo DiCaprio, Tom Berenger, Tom Hardy, Cillian Murphy, Marion Cotillard, Elliot Page, Ken Watanabe
Dom Cobb and his wife Mal created their own dream world for themselves. Until Mal began to believe that the dream world was real. Cobb performed the art of inception on her to make her realize that it was a dream. What Cobb didn't anticipate was that Mal would think the real world was a dream too. Mal kills herself to "wake up". Framed for her death, Cobb is on the run. When he fails to extract key information from the mind of businessman Saito, Saito strikes a deal with him: If Cobb can successfully incept an idea in the mind of Fischer, heir to a multibillion dollar empire, Saito will clear Cobb's name.
moviedragon
Chosen answer: The details are never explained in the depth, but all the dreamers are connected via the briefcase, so it seems likely that the briefcase acts in some way as a networking hub for them to share the dreamspace.
Tailkinker ★