I think we can chalk this up as another entry in the 'everybody thinks redheads look alike' list. Apparently, Jessica Chastain and Bryce Dallas Howard are regularly mistaken for one another, even though there isn't a particularly strong facial resemblance. Who'd have thought that so many people identify people they see by their hair before they look at anything else?
Both Chastain and Howard have actually worked together in the past, with both of them appearing in 'The Help'. They both dyed their hair for their respective parts. We're not sure if that was done because the parts called for it, or because their co-stars and the audience would have struggled to identify the characters if they didn't! Chastain came into acting through the famed and prestigious Juilliard School in New York, whereas Howard was born to do what she does; she's the daughter of director and 'Happy Days' star Ron Howard.