Hi atozey;
Welcome to the forum.
There have been reports of paint blistering in the areas where the paint had been removed by the previous owner. That may be the case here, and the owner decided to remove the damaged paint. Also the previous owner may have had plans to repaint it, but decided to sell it, as it looks like the previous owner used a sander to clean the side, and around the door frame. Just check periodically to see if blistering/flaking continues, and remove as necessary.
Other than than what Orion stated, the seasoning inside the cabinet looks good, and if you is not signs of mold, I would heat it at full temperature for about 10 - 15 minutes.