Marking the moment is a dramatic technique used to highlight a key moment in a scene or improvisation. This can be done in a number of different ways: for example through slow-motion, a freeze-frame, narration, thought-tracking or music. It has a similar effect to using a spotlight to focus attention on one area of the stage at a particular moment during a performance.
Marking the moment can happen when a scene has been created, and the group decides it's a significant moment in the drama, and they want to show this in some way. At times things happen in a scene very quickly - and yet we know these moments can change the whole direction of a drama. This is when something is needed to emphasize the moment.
The actors are to remain in the same groups and replay the scene but they must decide the moment of highest tension in the scene and mark it. There are several possibilities in marking the moment. But to start with, the simplest way to mark the moment is to freeze the scene, then moving on actors could also add a thought track each, use slow motion or deliver a monologue commenting on the action taking place and how they feel about it.