Loving that artwork. Who's the redhead with Hulk supposed to be? Scarlet Witch? If so I wonder why she has a S.H.E.I.L.D. logo on her shoulder.
It's black widow
Also since this is concept art it's likely they used some "Avengers" pictures as a reference.
Hulk is in the same pose as the Avengers movie
Set picture from Johannesburg of Hulk reference prop and hulk buster hand