Steven Spielberg's cinematographer Janusz Kaminski was brought on to act as a lighting consultant for Weta, as Jackson wanted the film to look "film noir-ish, and very atmospheric."
While their plane is falling from the sky, Haddock and Snowy drink blobs of floating alcohol while in zero gravity. This is a reference to a similar scene in the Tintin comic Explorers on the Moon.
At the end of the film, Tintin is letting the gold coins fall from his hand back into the globe; in the wide shot all the coins clearly fall from his hand. In the next shot, the last of the coins fall a second time.
Tintin's living room has net curtains in the windows when viewed from inside, but from outside they are not there, allowing somebody to spy on the Unicorn with binoculars.
If the film is set in the earlier 1930s then there should not have been a Citroën Traction Avant park up across the road from Tintin's flat. This car was produced between 1934-57. There are also several 2 CV Citroën in the streets. This car was produced between 1948 and 1990.
sThe following FAQ entries may contain spoilers. Only the biggest ones (if any) will be covered with spoiler tags. Spoiler tags have been used sparingly in order to make the page more readable.