This is just a thought....maybe if someone is outgoing, expressive, very social and happy with the previous person & not with you. Maybe they are mirroring that person's personality. Maybe just being yourself instead or mirroring someone else may be a way to really have people interact with who you really are.
I have found in checkout lines at the grocery when the checkout person seems rather grumpy I always engage them in good conversation & they are usually smiling & much happier than when they first started checking my groceries.
We need to engage, not mirror people if we want a quality interaction