This kind of thing is hardly new, or surprising. Cap is an emblem of America — it's no huge shock that in the US his visual position in the Avengers would be emphasized, while outside the US, it would be de-emphasized. International posters (and in multiple countries) often vary, depending on local preferences.
What's amusing is the folk who are somehow deeply offended by this.
Originally shared by +WILLIAM HUGHES:
Age of Ultron poster. USA versus international version