Nothing to do with delivery as such - just changes the throttle potentiometer programming!
From the factory the first 30% of throttle pedal movement equates to like 90% of engine load / power! So throttle movement to power is non linear
Linear map changes the throttle mapping so 30% of throttle travel gives you 30% power! So to get full power u do have to nail the throttle flat to floor.
It gives u greater throttle control basically - like mid cornering adjustability as you have more throttle travel to play with
Hope that helps