Q: "Two people wearing red hoodies ride their bikes down the street." Does this mean that "The bike riders are friends riding together."?
A: it is not possible to tell

Q: "This is a young man getting some airtime on his skateboard." Does this mean that "A young man is on his skateboard."?
A: yes

Q: "A man in a dark pants lifts his leg while five girls wearing rollerskates gather near him." Does this mean that "An adult with kids gather close to each other."?
A: yes

Q: "People sitting on the side of a lake." Does this mean that "The people sit near an indoor pool."?
A:
no