2013 MBA Display problem (or is it?)

Hello

I just realised something with my display and found its reason very fast. When I set my brightness to lowest to turn off the backlight, the middle of the screen stays somewhat lit (very low but visible, check the attached pictures). As I am writing this, the Apple logo on the back of the display is somewhat visible so that's where the light comes from, although I can't take its picture. Basically in the middle of my screen there is a part the shape of an apple, which is lit a bit more than the rest. Is this normal or does it require a replacement?

UPDATE/EDIT: After some research I found out, that it is actually how the computer's display is made. For people who are wondering the same thing, basically the Apple logo is lit by the same LEDs, that light the display. So if there is a light source much brighter than your LED backlight, you will see the logo.
I found out, that setting the brightness a little bit higher than usual and/or tilting the display a bit more backwards makes it disappear.