Sorry, I meant it's a giveaway about them steering their partner around the floor. If the lady is dancing her steps and following her partner's lead correctly, then the frame is light and easy. The second the man's hand drops from her shoulder blade he is having to manoeuvre her into position because she's either a) not keeping up; b) gone off time; or c) forgotten her steps.
If you are dancing correctly you should be able to dance it without contact through the arms at all - the majority of leads come from contact through the body - hence why gapping is such an issue.