Ghosts in the attic?

I was recently going through some photos I took during a recent trip to Chicago when I came across this front view of my late grandmother’s house.

However, when I zoomed in for a closer look at the attic windows, I noticed something unusual.

There appear to be two faces at the windows. The face on the right does seem to resemble my late grandfather who passed away in 1981. Or this whole thing could be an illusion created by clouds reflected in the glass. I’ll leave it up to the Internet community to decide, but I will state that this photo has not been tampered with or altered in any way.