Manipulation? Dog doesn't know nor care what it looks like. Can't even recognize itself in a mirror.
This is the dog's "I love you" look. If you don't get that look from your dog then it's not your dog. No manipulation. Just expression.
As for the genetics, turns out if you say "I love you" to a human often enough they'll return the feeling and feed you and breed you.
Eschew obfuscation. Habituate elucidation.