Sorry about that issue FFNasca :(
You have to get the animals in the center of the screen and ignore the hud image of the camera.
It was a poor UI choice in retrospect, it hadn't occured to me that it would be confusing, I guess I was too close to it. Think of the camera like it's a gun in Doom, purely aesthetic and you are really aiming with the center of the screen.
A couple of other issues are that if you photograph an animal that isn't on the check list the camera doesn't move and you get a miss, also if the animal is too far away (outside of camera range) you will get a miss which is an issue some times for animals in trees.
These things weren't obvious and clearly bad decisions in hind sight.
Ran out of time to play test on other people, this would have been caught instantly I think if I had done so.
If you are interested, keep an eye out for some updates which hopefully will come in the next couple of weeks which will fix a lot of these issues and also add some more flavour to the world itself :)