What Is That ‘Face’ In The Window?

To help celebrate my birthday this past weekend, Perry invited my family to come to his father's weekend home.

The kids were gathered around the table playing a game when mother took advantage of the rare moment they're playing quietly together and snapped a picture. Later that night, I received a text from her. You can read our exchange below:

After examining the picture in question for a few minutes, I found the image she was referring to. Initially, I thought her assertion was silly, but after Perry and I were unable to recreate the reflection, I found the mystery a little disturbing.

I still don't think it's a face and there's a rational explanation for the reflection but I'm at a loss to describe exactly what it is.

So, I need your help. Can you identify what's in the red circle? Perry and I ruled out the television and computer, but could find no other potential sources for the reflection.