Dogs tail was sticking straight out which means it was curious. He was probably wondering why he saw the shape of a cat but couldn't smell the stank of a cat. His tail started wagging when the man approached and he knocked down the cat decoration in front of him because he was anything but scared.
"If a dog is stressed or anxious, they will keep their tail lowered between their legs and when they are scared they will hide the tail under their body.
However, a vertical tail indicates aggression or a dominant attitude.
© DogHealth.com"