I like the photo of your wife for the challenge because I think that if she was removed from the photo it would leave her outline, kind of like those silhouette paper portraits that were just black and white, and that to me is an example of negative space. I'm leaving a link as an attempt to clarify what I am getting at: https://en.wikipedia.org/wiki/Silhouette
The second photo, I like the way you processed that one.
Cheers, Amy