Although he only appears briefly, the Buy-N-Large CEO tells us a lot about what a mess humans of made of Earth.
His first appearance is shocking because he's a human in a cartoon, like Bob Hoskins in Who Framed Roger Rabbit? His human appearance serves to ground WALL-E in reality, and serve as a warning that this could happen if we continue down this path.
But what is this path? Namely, it's not taking things seriously. This is a world in which a corporation like has taken over, and its CEO basically acts as President. President of the freaking world.
After the planet is totally trashed, he doesn't seem to care. Simply hop on the Axiom and blast into space! "Space is the final fun-tier!" he says as if the destruction of Earth is just a snow day earning people a few hours off of work and school.
When he appears again, in the Directive A113 video, his clothes are disheveled. He admits that the plan to clean up and recolonize Earth has failed. While he seems defeated, he still has a strange, chipper of talking, saying "golly gee" and smiling at the camera even as Earth crumbles around him.
It's unclear what happens to the CEO. He's donning a life vest in that last video. Wherever he went, let's hope those people that went with him never get to return and screw things up all over again.