Yes, those are hard spots, caused by a slippy clutch overheating the friction surfaces. I've eliminated a lot of clutch chatter problems by replacing motor mounts. That one doesn't look too bad, but as the rest of the surface wears, the hard spots become high spots. A temporary fix can be had by refacing the flywheel with a surface grinder instead of a carbide cutting bit to get the hardened areas level with the rest of the friction face.
Jerry
