The Repetition Exercise can be adapted in many ways, teaching actors to avoid a thought-driven, self-conscious approach. It is not a standalone exercise, but a fundamental mechanism that exists within the actor: I observe something outside of myself, I form my opinion and feeling about it (love it or hate it), I throw that back at the other actor, and wait for their response, then repeat it all over again. This is the basic mechanism needed in dialogue or scene work, and can also be applied to working through a monologue. By allowing moment to moment responses to the text, you can effectively make the text your partner.
From the outside, repetition appears quite a strange exercise, because it is training actors in working with non-verbal communication. There is much more to it than ‘You have a blue skirt’. Repetition is the scales to the pianist, the sketchpad to the artist.