Cortijo Fain Ghost Picture

"I took this picture with the cell of a friend of mine at his wedding party, last June. We were in a resort called 'Cortijo Fain' close to Arcos de la Frontera, Spain. The owner of the resort told us that it was a clausure convent during the Middle Ages. On the left of the tree I see a clear figure of a nun. What do you think about? I'm sure the the picture is artless (not tampered with), because I took it personally and I almost immediately realized that there was something weird with it. I have also zoomed in on it and it looks like a face."