@brendan this other photo may clear things up, the zipper is aligned to this strip underneath that I need to keep flat, it also helps me keep things in alignment. If i were to sew it face up i wouldnt see what im doing (keep in mind, im a bit of a newbie, and was following instructions from a video).
I ripped out the seams on the other side to reveal the zipper underneath (second photo).
@rek ah, I get it now. Thanks for the excellent clarification!