Hi,
I made a drawing to show the relations.
It is all about leverage.
The foot force will spread equally to both cylinders, but when we move the bar we have a different leverage [arm].
Because we change the distance [arm] between the clevis to the brake pedal the force at the pedal [for that cylinder] will be heavier or lighter, if we shorten or enlarge the distance.
Shorter = Heavier
Large = Light
We know that the [line pressure] is = [Force] divided [surface]
So we can conclude that there will be a different in line pressure due to the change in leverage.
Regards,
Cobra289