A man on one miniature train passes a circular object to a man on another train as they pass by.
Two trains of different sizes but following each other side by side going to opposing directions.
One cannot both pass by and follow each other.  Just because one man is on a miniature train, it does not necessarily mean that the two trains are different sizes.
it never stated that the trains were different sizes.
Just because one train is miniature doesn't mean the other train is a different size.