He did a frame by frame roto of Obi Wan walking out of frame as Anakin is about to say "she hardly even recognised me, Jar Jar" and flopped him (final cut term - means flipped :-p) horizontally as well as scaling him down slightly so he looks further away so he looks like he's walking back on himself in a circle.

He does this because he cut all the whiny dialogue (and Jar Jar talking!) which doesn't give Obi Wan time to have made it back around without it.

As for the other rotoscope you're asking about, I have no idea...I didn't know there was one.