Sometimes your body language is enough for an actor to know that you're not happy. And you don't really need to say it out loud if you deal with actors you know very well. And I don't think you really need to be explicit. ↗
I directed 24's pilot. I felt we should follow the characters around as if we were a documentary crew, using available light, hand-held cameras, split screens, sound that isn't always what it should be, to suit the reality of the premise. ↗