I think when you say the photos are taken by chickens, I was imagining a chicken wearing a GoPro or something. These are motion-activated pictures from a stationary camera. They're still very cool though.
My thought too. When I saw it was just a home made camera trap I was a little deflated. Their claim that it is the same as human selfie because the chicken is "using" the motion sensor as an input device is a bit of a stretch. The pictures are fun though.
Their claim is also 100% wrong. The difference, of course, is intent. It's easy enough to ferret out the difference here: If you set up such a motion-triggered camera and a person walks through it, unknowingly resulting in a picture being taken, is it their picture?