They were originally drawn with brushes, and the stroke direction was obvious. In handwriting, you're also supposed to use the same stroke order and direction.

They were originally drawn with brushes, and the stroke direction was obvious. In handwriting, you're also supposed to use the same stroke order and direction. A font doesn't have that, so some fonts use differences in shape and thickness of the line to indicate the stroke direction. So I'd say that the difference is mostly how your font chose to indicate the proper stroke direction.