In the video where the person initially walks up the walkway, there are no eyebrows visible. It's only when the person gets closer to the camera and moves his head that a shadow appears where it was clear before.
-PJ
To anyone who has kept up with this better than I have:
Do we know for sure that Nancy returned to her home? Could someone have taken her phone and apple watch back to the house to make it look like she returned? Are they just taking the family’s word about the time she returned home?