"Well, I think one of the main things that you have to think about when acting in the movies is to try not to make the acting show"

In this quote, James Stewart is stressing the importance of subtlety in acting for the motion pictures. He is suggesting that actors ought to aim to make their performances appear natural and uncomplicated, instead of overly theatrical. He is highlighting the value of making the audience believe in the character and the story, rather than being sidetracked by the star's performance. Stewart is suggesting that the best performances are those that are not excessively snazzy, however instead are subtle and nuanced. He is emphasizing the value of developing a credible character and story, rather than simply trying to display one's acting skills. By doing this, the audience will be more engaged and invested in the story, instead of being sidetracked by the actor's efficiency.