Dogs are the only species of animals, except for the people themselves, who can recognize our emotions. They have a quick glance to see if you are happy, embarrassed, angry or sad. They are able even to empathize with people, feeling the same emotions that their people.
I have noticed that with Keira, even more when she is working with senior citizens in hospitals/retirement homes. It's amazing how much her attitude and mannerisms change from person to person.