Two homeless men dressed in gray sit against a wall with a sleeping dog on a purple leash.
Two friends sit against a wall with their pet dog.
Not all homeless men are friends and nothing says that the dog is their pet dog.
Not all homeless men are friends. Two men with a sleeping dog on a purple leash doesn't necessarily mean that it is their pet dog
The two men may not have been friends.So if the dog only belonged to one of them, then it would not be their dog.