this killer did go to extreme lengths to conceal her identity - from what I can tell from staring at all the screen captures from the MPD surveillance video - she not only had a balaclava, but also a face guard, and it appears to me that she even has a couple of face masks
and at one point they are dangling from her neck (and I had previously studied these masks at length and I posted that one looked like a baby's face and it was driving me crazy.) But anyway at certain segments she pulls the balaclava down, pulls a mask down, etc so at different segments you can see various areas of the face and eyes clearer than others. I was looking online for the type of mask it might be and found some masks that people use to apply makeup on that look similar. Here's a couple links:
http://store.makeupart.net/complete-make-up-mannequin-tool-kit--p57.aspx
http://www.giell.com/makeup-and-mas...mannequin-head-and-mask-set-by-celebrity.html
I can't explain why you can see the outline of her face as she is walking into the alcove other than the lighting/shadows changes throughout the video depending on where she is. But I definitely believe it is the outline of her face that is visible. You cannot see her eyes because there is a shadow from the glare above from the flashlight.