Photos of real owls
This is a long earred owl named Nemo. He was startled by an unusual sound. As a natural response, he immediately puffed up to a very large size in order to scare off the perpetrator. It is rare to experience this kind of reaction in an owl. Nemo went back to normal size when he discovered that the threat wasn't real.
Threat Display - Picture 5 in Owl Physiology: Behaviour
Barn Owl (Tyto alba affinis) - Picture 10 in Tyto: alba
Tawny Owl (Strix aluco) at hollow - Picture 6 in Strix: aluco