Trust
They never met before, they never saw each other. They met just a few seconds before but they trusted each other from the first moment they met. That is incredible. Yes, that is a proof ! There is indeed an emotional layer between beings. So use it !
Look into the dogs blue eyes and you believe it as well.
Olympus E-5, 1/160 second, f5.6, 50 mm focal length, no flash used. Just a quick shot from the hip