Maybe Serena saw this as her career transition to full-time SJW, but I think it’s even simpler; she was counting on all the drama to unnerve Osaka in her first grand slam final - and I’d bet on it working against the majority of inexperienced opponents. You see a racket smashed, the crowd starts to murmur or jeer, and next thing you know, Serena’s run the table on you.
And I will add, Serena used to take acting lessons back in the day.