匠 jiàng is his profession. 石 Shí is his family name. 匠 jiàng are cited numerous times in Zhuangzi as people who alter raw material. "Carpenter" would be a natural translation, especially since he is looking at a tree. But since his last name is 石 Shí Stone, I decided on something a little broader.
At one point he is referred to as 匠伯 jiàngbó, which the commentators agree is his first name. Since it sounded odd to me to include his first name only once and for no reason, I did something equally odd and translated it Bob.