Ah I think I see what you’re getting at. I thought you were saying it’s a dog’s unique ability to convey emotions specifically to humans by mirroring our behavior that made them more valuable than other animals.

It sounds like you’re saying they have emotions that other animals do not.

While it’s true we can’t measure emotional intensity in animals, we can certainly observe their behavior and see that they will cower, flee or scream to indicate fear, and call out or wail to indicate sadness (something that has been observed in dairy cows separated from their calfs). I think anyone who’s spent time around these animals would agree that they certainly have the capacity to feel these emotions, and I don’t see why that’s any different from dogs.