Q: "A boy wearing a backpack is standing outside." Does this mean that "a child is standing"?
A: yes

Q: "A person is skiing." Does this mean that "The person skis."?
A: yes

Q: "A football player for the Sooners is preparing for the next play during a game." Does this mean that "A player is holding a ball."?
A: it is not possible to tell

Q: "A young adult looking through the lens of a large telescope." Does this mean that "The young boy is searching for something in the sky."?
A:
it is not possible to tell