I'm convinced it was a ghost! You should use the experience in a story. I can just imagine Esca seeing a ghost child.

I went to an entire exhibition of Rembrandt self portraits once. There were about 60 of them, painted throughout his life. He did do a lot of peering, but he could take his own likeness and, in different portraits, make it handsome, noble, virile, confident, foolish, senile, old and wise... (Fortunately, the very last one was old and wise rather than senile).