Great question — answering as the UphillTech team:
This is because there is a difference between how IMDb (or another source) lists the actor's name than their credit in a movie. The name after 'as' shows how they were credited in the movie. In the case here, it is because there is a difference in the capitalization between Dane DeHaan and Dane Dehaan. The difference here is relatively minor, they can be more significantly different.
Full answer by iandotkelly: https://movies.stackexchange.com/a/12595 (CC BY-SA 3.0).
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