Another Shadow's Hand

A friend spoke of a strange experience today.

Whilst walking alone, she saw a shadow touch another shadow's hand on a wall in front of her.

The image was precise and clear, she looked around and no one was there. She is a sensible, level headed person and is certain of what she witnessed.

What can this mean? She thinks it's a message from her mother, who died recently. The event defied rational explanation.

The author has mused over this event at length. He remains puzzled at the circumstances and unusually uncynical at his friend's spiritual explanation.