Activity zone question

The newer grid detection zone confuses me.
Is it the black area that detects motion or the non-black area?

The non-highlighted squares are excluded from detection.


Highlighted squares are the black ones?


Ok, I get it, but I found your original answer confusing. If all the squares are black then the ones you clear would be the highlighted ones and the black ones are the non-highlighted ones. Anyways thank you for the clarification.