Q: "People waiting for a train." Does this mean that "Humans at a station."?
A: yes

Q: "A young boy and girl in swimsuits play in the sand at the beach." Does this mean that "a boy and girl play at the park"?
A: no

Q: "People rock crawl up a steep obstacle." Does this mean that "People slide over a surface."?
A: yes

Q: "two teenage females are posing near a body of water." Does this mean that "There are two teenage females who are at a beach."?
A:
it is not possible to tell