This helps but I still don't see it in the original image
I only see a young woman's head turned and looking at the window
Edit: squinting makes me see it, I guess my mind doesn't register the old woman until I see less detail but I still don't see it in the original image op posted
I don't think the original image in this post has enough detail to create the illusion
I can see it but it’s tough. Could only see it at first because I knew to look for something. It doesn’t help that the first thing you see is such a small pretty face, then when you have to look for the old woman you need to look for enormous somewhat grotesque features.