What actually happens when I 'enable airbrush-style build-up effects'?

I currently have a blank layer open, filled with the colour white.

I've been painting strokes of black onto the layer, firstly with 'enable airbrush-style build-up effects' on. Then with it off.

I have my brush on 100% opacity and 10% flow when 'enable airbrush-style build-up effects' is both on and off.

I am unable to see the difference between the different strokes of brush, after having brushed several times (10 each) with the effect on and off.

I have an idea of what the effect is suppose to do, however as I am not seeing any change my mind isn't fully understanding.

Also: Yes I already restarted Photoshop to make sure the program wasn't glitching.

Lastly, thank you in advance for any comments and posts, which are helpful and informative.