Q: "A security officer and a man stand in front of a building." Does this mean that "A security officer stands alone in front of a building."?
A: no

Q: "Two dogs are running in a grassy field." Does this mean that "Dogs are playing fetch."?
A: it is not possible to tell

Q: "Two men are singing together and one is playing guitar." Does this mean that "The men are singing and playing guitar outside."?
A: it is not possible to tell

Q: "A little girl splashes in a pool of water." Does this mean that "There is a girl in the water."?
A:
yes