How does Bierce describe the rider ? What metaphors does he incorporate?

From the text:

The figure of the man sat the figure of the horse, straight and soldierly, but with the repose of a Grecian god carved in the marble which limits the suggestion of activity. The gray costume harmonized with its aërial background; the metal of accoutrement and caparison was softened and subdued by the shadow; the animal’s skin had no points of high light. A carbine strikingly foreshortened lay across the pommel of the saddle, kept in place by the right
hand grasping it at the “grip”; the left hand, holding the bridle rein, was invisible. In silhouette against the sky the profile of the horse was cut with the sharpness of a cameo; it looked across the heights of air to the confronting cliffs beyond. The face of the rider, turned slightly away, showed only an outline of temple and beard; he was looking downward to the bottom of the valley.