I’m fascinated by this, after a very insistent trainer years ago told me that a shake off was
definitely a negative sign of stress. She’s absolutely wrong, and I’m certain that it’s far more nuanced and neutral than that. My observation is it’s when there’s a change of pace, or some ambiguity, or a decision’s been made - a bit like humans take a slightly deeper breath, or raise eyebrows, or say ‘right!’. Or ‘okey doke’ like I do

. So maybe a release of tension, but sometimes positive, sometimes negative, sometimes neutral. I now suggest (rather than ‘cue’) it, and 9 x out of 10 get a response.