The Two Ravens is the best photograph because of the composition.
In the front are two ravens with their back facing the viewer, 
in the middle is a small bird and at the back we see red roses and other vegetations.
All these elements form an interesting layer effect where different things overlap on top of one another.
The photo also has a very clear light source as the bottom left corner is much darker than the rest of the picture and it gets lighter gradually towards the top right corner.