Q: "A man sits on a raft in the sea" Does this mean that "There is a raft."?
A: yes

Q: "Two males on a rock over water, one in midair jumping into the water." Does this mean that "Two boys push a boy in the water."?
A: no

Q: "Motorcyclist racing on a track with a yellow dirt bike and a Kawasaki-branded green advertisement sign." Does this mean that "A person is racing on a track."?
A: yes

Q: "An older man in a rust colored t-shirt attempts to play a black umbrella like a violin." Does this mean that "A human in a shirt"?
A:
yes