The image, which shows the tense meeting after the wizard (Ian McKellen) and his dwarf companions are surprised by the monsters after seeking refuge in a mountain cave, debuted on Entertainment Weekly's Facebook page.
In the confusion of the kidnapping, Bilbo (Martin Freeman) is lost and has a fateful encounter with Gollum (Andy Serkis).
McKellen recently claimed that Gandalf would beat Magneto - who he has also portrayed in the 20th Century Fox X-Men films - in a fight.
Director Peter Jackson has said that he does not think that the first film in his forthcoming trilogy will be recognised at the Oscars.
The cast also includes Cate Blanchett, Orlando Bloom, Ian Holm, Christopher Lee, Hugo Weaving, Elijah Wood, Evangeline Lilly and Richard Armitage.
The Hobbit: An Unexpected Journey will debut on December 13 in the UK and December 14 in the US.
Gallery - The Hobbit: An Unexpected Journey: