Akbar called Birbal to draw a Line

Akbar called Birbal and asked him to draw a line on the floor.
He asked Birbal to make that line smaller without erasing it.
Birbal smiled and did it before Akbar could blink his eyes.

How did he managed to do it?

Click here for Answer

Birbal drew another line that was larger than the First Line.
So now the first drawn line was smaller.