The scene showcases Bilbo's climbing skills after the company reaches a swamp, which they've been warned by Gandalf holds some dark enchantments. That doesn't appear to stop the dwarves though, who encourage Bilbo to cross as he's the lightest.
Check out the scene below:
There will be a total of 25-minutes of additional and extended scenes for The Hobbit: The Desolation of Smaug Extended Edition. It's going to show some intriguing new moments from Bilbo's journey.
You can grab a copy of the The Hobbit: The Desolation of Smaug Extended Edition on November 3rd on 3D Blu-Ray (and it's native 3D of course - shot on 3ality Technica rigs), 2D Blu-Ray, and DVD, a month before The Hobbit: The Battle of the Five Armies hits theaters on December 17th, 2014 in IMAX 3D, RealD 3D, HFR 3D, and regular flavor 2D.