These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: The Iron Giant
Accidental Aesop: The Giant's emulation of Superman and dislike of the villainous robot Atomo shows the importance of role models and positive representation in media.
Is this an Accidental Aesop, or is it a deliberate part of the movie's message about choosing who we want to be?
Also, Kent Mansley saying "Screw the Country! I Wanna Live" as his final lines in the movie after he unwittingly sent a nuke directly into the town becomes extremely ironic when the President in Shadow the Hedgehog (who is strongly implied to be the same president from Sonic Adventure 2) is redesigned to resemble Kent Mansley.
For publicity, Eli Marienthal (Hogarth) did an interview with Scouting magazine Boys' Life. The magazine itself gets a mention in the film as Hogarth is showing his comics to the Giant...although not quite the one they would want.
Moral Event Horizon: Mansley marches across one after another, no doubt muttering "I Did What I Had to Do" each time. He rents a room under false pretenses, steals Hogarth's photos for his own use, interrogates and drugs the boy, threatens to have him taken away from his only living parent, lies about the boy being killed to provoke a military response, and eventually subverts the chain of command by ordering a nuclear strike. (And even when he regrets that last one, it doesn't seem to be What Have I Done, just a realization that he's standing on ground zero.) And just in case you haven't started to despise him yet, he establishes his Dirty Coward creds by assaulting a soldier, stealing a military vehicle and trying to get away. At least the Giant stops him and the General gives Mansley what he deserves.
The film was universally loved by critics, but that didn't save the film from bombing at the box office; Warner Bros.' marketing blitz for the home video release (as well as Cartoon Network airing the film numerous times in the past few years) led to the film being seen by a wider audience, and now it's considered a modern animation classic.
Cartoon Network once did a Memorial Day special of airing the movie over and over and over and over and over again back-to-back, three days in a row.