The scientists had used publicly accessible photos of Hanks to build a 3-dimensional design, or "mesh," of his face on to which they projected his characteristic expressions.
During the Entish assault on Isengard, one particular of them catches hearth. As the Ents split the dam overlooking Isengard, there is an Ent in the foreground holding a struggling orc in his hand. There is a shot of the Ring lying in the snow in the foreground.