It is oft-times said that the eyes are window to the soul. It seems to me that, especially in the case of the eyes of animals, that the eyes are the mirror of the onlooker’s soul.
Man looks into the falcon’s eye and feels a deep and abiding respect.
Man looks into the raven’s eye and feels the cold grip of fear.
Man respects the falcons ferocity and his simplicity of purpose. Man fears the cunning and the complex wisdom of the raven.
This, I suppose, makes sense; it is Man’s nature to respect power if he can predict how it will be used, but to fear wisdom and cunning whose aims and means he cannot fathom.