Q: "A man in a blue shirt and safety glasses grinds a piece of metal which throws sparks." Does this mean that "The man is a welder."?
A: it is not possible to tell

Q: "A bald man is looking out at a crowd of people." Does this mean that "A man who is bald looks out at the crowd of people."?
A: yes

Q: "A hooded man working in a kiosk displays his wares." Does this mean that "A man has arranged his wares in a kiosk for display"?
A: yes

Q: "Single man in empty brick area playing the saxophone." Does this mean that "Man playing a saxophone."?
A:
yes