In the words of Katherine Hepburn as she watched one of Streep’s performances “Tick tock, tick tock”. You can’t see the gears working when watching the truly great ones. It’s the difference between art and craft.
Streeps’ acting has always been “Meryl Streep performing as X” rather than simply “X”. That is bad acting, but it is often praised. It often wins awards, too. Actors who simply become “X” don’t stand out. They don’t get attention. And awards go to ‘performances’ that are noticed.
A little off topic, but what is the difference between "art and craft"? I believe they are synonyms to each other. Serious question.