What differentiates? The motion of the bat is similar to a bunt that is not shown early.
Both cases bat goes down from shoulder to ball stopping on contact.
Did you bother to read the definition of a drag bunt? The difference is, swinging to contact with the intent to hit the ball with force vs sticking the bat out and just dragging it along with the motion of the batters body. 2 completely different actions with 2 completely different intents. Its not that hard to differentiate.