Service dog reacts and does as he was trained to break her anxiety

Someone said dog's sniffers can detect anxiety, and possibly internal medical conditions (cancer).

Edit from 2016: https://news.nationalgeographic.com/2016/03/160319-dogs-diabetes-health-cancer-animals-science/

Highlighting that it's probably scent that triggers the animal's response, more than human behavior.

the main training is to break her hands apart and distract her... this is a good example of a properly trained service dog for this need