Continuity mistake: When Diana escapes from the guy who had kidnapped the boy, she runs into the woods wearing a dress. When she starts to turn into Wonder Woman, she is somehow now wearing pants just before she changes into Wonder Woman.
Visible crew/equipment: When the hit-man is loading his gun in the alley in preparation to kill Diana, a crew member is reflected in the storefront "Humburgers" window.
Answer: The transformation twirling was invented for the 1970s TV series only, to explain her quick change from Diana Prince to Wonder Woman. However, it would have been nice to do a little spin homage in the movie.