On first glance, the exaggerated depht effect seems to result from lightly polishing the surface of a strongly patinated plate. Thus, all edges are highlighted, leaving the cavities dark. But this would also help to obscure other faults. The details seem rather coars on some spots like the hatched bands on the lion´s body - what do you think, arent the vertical lines spaced too far?. A larger image would help a lot.
It also seems impossible to pull the rear spine out of the spike base like that without breaking someting. At least the upper brad of the spine should be damaged. Maybe the spike was also tilted forwards in this action, resulting in the damage that spikeymikey mentioned.