The five original phony frames were cropped differently from one another.
This makes the entire scene jerk about when animated.
The second frame in
particular had the edges rounded to make it look like the camera was in
a housing, but this effect was not continued through the other frames.
It is much more likely that the inpainting on the corners of the original second frame is to hide something interesting that we weren't supposed to see.
http://www.911review.org/images/pentanimorig.gif
What is going on in the upper
corner?
What is there a big gray splotch in the second frame?
Notice how fast the frames move to trick the eye into seeing motion. The SBD animation solves this problem with interframes.
