The whole left side of this portrait is carefully worked with the flat chisel. This is the remnant of the original carving. The side of the beard and back of the hair, as well as the ears (which are now too large for the reworked face) are all original.
The face has been roughly re-modelled with the flat chisel.
Notes
This portrait was found in the Sculptor's Workshop and consists of a finished bust of a philosopher (or other bearded individual) which was in the process of being re-carved.