Q: "Two police officers on mopeds, side by side." Does this mean that "Two officers are patrolling on a moped"?
A: yes

Q: "A group of men in uniform and formation carrying trumpets." Does this mean that "the men are in a band"?
A: it is not possible to tell

Q: "Several young girls on colorful mats stretching upwards." Does this mean that "There is more than one girl."?
A: yes

Q: "A person walking down an empty street." Does this mean that "The person is alone on the street."?
A:
yes