I wanted to point out one little thing before I go back and watch the rest of the sequences. But, I noticed another nifty little thing Jackson and Co. added to the movies. Here's another comparison picture...
Frodo and Gollum are both trapped in the Ring. Though Frodo is not fully inside the ring. He's only about half-way covered by the Ring, so it shows already that he's getting taken over by the Ring. However, he's not to the extent of Gollum as he is fully encompassed in the Ring. His fate lies with that of the Ring, the Ring has total control over him, and there is no more chance of being saved. He is "encircled" in the Ring. Where Frodo is only partially at this point in Bree.