There are three possiblities:
1. Faye Dunaway simply assumed La La Land would win, and announced it - but this is unlikely. Not only is she an experienced actress and knew hundreds of millions of people were watching, but she knows how to read scripts.
2. Faye Dunaway was told or given the info that La La Land had won prior, and she thought reading the envelope was a formality.
3. Faye Dunaway knew the Oscars had switched Moonlight as the "winner" at the last moment, and she decided to sabotage the whole shebang.
During the 2015 Miss Universe pagant, the wrong name was read, but there were two names on the card.
Not so here:
A Staged Hollywood publicity stunt to end all publicity stunts.
Staging stunts-—this is what they do for a living, for God’s sake.
And never forget these are the world’s best actors onstage in front of the cameras they live for ..... pretending they’re reading off cards.
Beatty’s fake pause...chirpy Dunaway’s chiming in act......then the show’s producers ready and waiting in the wings to storm in w/ the right card.
Caustic social critic—Camille Paglia-—had it right. The grandeur of the awards is gone.
So they had to do something to get attention.
Steve Harvey has to secretly be really happy with this. His flub is minor by comparison.
There's a fourth possibility.
Beatty was given an envelope that contained a card that said, 'Emma Stone', and underneath, 'La La Land'.
Beatty was confused and handed the card to Dunaway, who interpreted it to mean La La Land won Best Picture.
IOW, someone at PWC put a duplicate of the Best Actress card inside the envelope meant to be read when awarding Best Picture.
Or, at least that's what I saw when I was watching the show.
What did you see?
My guess is she thought Beatty was pulling her leg, just clowning for the camera or trying to annoy her. She took a quick look at the card, saw “LaLaLand” and read it. She didn’t see “Emma Stone” on the card and wasn’t looking for anything like that. I don’t think she was in a scrutinizing mode. She just assumed things were straightforward and Warren was just putting on a stupid stunt.