Conversation so far:
What was the revelation that shaped Lee Strasberg's life?
H]e observed, first of all, that all the actors, whether they were playing leads or small parts, worked with the same commitment and intensity.
Where did he observe the actors?
when Stanislavski brought his Moscow Art Theatre to the United States in 1923.

Question: What was unique about these actors?
Self-contained rewrite: What was unique about the actors from the Moscow Art Theatre?