Q: "A white dog is standing by a river shaking himself dry." Does this mean that "A dog is shaking himself dry because it just stopped raining."?
A: it is not possible to tell

Q: "A guy dressed in blue shirt and shorts leaps over blue tube while children watch in background." Does this mean that "children are watching a man"?
A: yes

Q: "A man is sitting inside of a mailbox with a phone in his hand." Does this mean that "A boy is selling lemonade."?
A: no

Q: "Two people wearing backpacks cross a rickety chain bridge, which is above a flowing river." Does this mean that "Two people are wearing backpacks."?
A:
yes