Q: "Two firemen turning the water on in the hoses." Does this mean that "Two firemen need both hoses to douse the flames."?
A: it is not possible to tell

Q: "A man wearing a gray shirt is playing guitar." Does this mean that "A tall human in a shirt"?
A: it is not possible to tell

Q: "An unkempt frowning old man with white hair is sitting in front of a chain-linked fence." Does this mean that "the man had brown hair and was driving the bus all day"?
A: no

Q: "A young man with a camera is sitting in a train while grass goes by outside." Does this mean that "The young man is taking pictures."?
A:
it is not possible to tell