Marvel sued for Iron Man copyright infringement

[Don]

This is from some company called Horizon Comics. They also said Ant Man copied their design because they've some guy wearing a gas mask too.

I've seen a lot of similar stuff in manga too. This reminds me of a conversation in Chu Liu Xiang:

Main character: "There are five dead people which seems to have nothing in common in them, but I'm sure it's a mass murdering plot."
Smart girl: "I figured out their common traits. They are all human."

It amazes me so many people think everyone pays attention to their totally irrelevant fictional work. Here I can see people try to make a buck suing Marvel, but you'd also see people post similar pictures like "Unknown Work A shows a guy flexing his muscle" "Unknown Work B shows a guy flexing his muscle". Therefore B must have stolen from A.

[Julius Seeker]

I've worked alongside art directors for major corporations before (including items under the Disney umbrella), you'd be surprised how often they "reference" other people's work. Usually artists will hit up the legal team to mitigate any suing. My guess is they looked at this and said the orange and darker grey would be fine because it's such a common colour combo in marketing material. It could also be that they were both following the same rules, and (as you mentioned) that's not exactly an uncommon pose, so there is the likelihood it's a coincidence.

[Don]

I'm sure artist will go 'that pose looks pretty cool' or 'this mech design is pretty good', but you can't copyright stuff like 'a guy wearing mostly red full body armor.' Most art is inspired by preexisting works and it's not like there is exactly a large number of original designs that nobody else has ever thought of in general. Sure there are works that looks like wholesale stealing of ideas but those are usually stuff where everything looks exactly the same. Just because Darth Vader is an iconic villain doesn't mean nobody can ever have a bad guy wearing a black helmet wielding a laser sword.