Jennifer Aniston revealed that guest stars on Friends were often nervous

Jennifer Aniston revealed that Guest stars on "Friends" were often nervous. 

Jennifer Aniston shared with Lisa Kudrow for an episode of Actors on Actors, "The movie stars that came on "Friends": Brad, Bruce Willis, Julia Roberts, Isabella Rossellini — we had so many — Sean Penn. They were always nervous".

"Remember? I always found it fascinating how nervous they were."

Lisa responded, "Well, because what's the tone?. It's not theater; it's for TV. It's not a movie. What the hell is this? And it's a good question. And I remember someone asked one time. I didn't know how to explain it, so I said, 'Oh, just talk louder. Same intention, just [louder].'"