Well, she probably watched lots of videos about Holmes and read a lot about her in preparation for her role. IIRC Tina Fey talked a lot about Sarah Palin.
And “the point” is that it is an interesting twist to have an actor who portrayed a public figure actually interact with that figure.
Then what was the point of bringing Amanda Seyfried into the "documentary" as a major character?
What does Amanda Seyfried actually have to do with the story of Elizabeth Holmes and Theranos?