The audience mainly triggers their feelings about the emotions of the characters in the film through the plot of the film, rather than the actors performing some expressions according to the plot of the film.
Zero-degree performance is boring in understanding, so almost all books will quote a film called Queen Christina filmed by 1933 when talking about zero-degree performance.
Extended data
Example:
When Queen Christina rode out, she met Count Antonio, the Spanish envoy. His carriage was stuck in the snow and could not move. Christine couldn't help laughing when she watched his entourage in a mess. It turned out that the two were "not friends".
Laughter in this shot: Garbo thinks Christine will not laugh as a queen, while director Ma Marion thinks that without the queen's laughter, there will be no first conflict between two people.