I only wish I knew how much of Leia’s sudden personality shift midway through A New Hope was by design, and how much was just weird George Lucas writing quirkiness or a symptom of multiple rewrites by George’s 1970s friends.

The accent shift doesn’t seem intentional, but maybe I’m wrong. Leia speaks with her “Act I accent” when talking to Vader and Tarkin, but also when talking to allies like Obi Wan (via the recording stored in R2). She drops the accent when she meets Luke. So maybe the accent is some kind of “formal speech” used when speaking with dignitaries? But then at the end of the movie, when she arrives at Yavin IV, she does not resume speaking with her “Act I accent” when she’s talking with the Rebel elite like Dodonna (at least I don’t think she does… might have to double check.)

Also, people always say Leia has a British accent during the first half of A New Hope, but to me it actually sounds closer to an old 1930s/40s Trans-Atlantic accent used by the American upper class.

It’s also funny to observe that the destruction of Alderaan seems to be the event that triggers her accent change.