The second-hand book of blank pages

An original fictional scene set at an invented book stall.

The book had a handsome green cover and no words inside. I turned several pages before believing it. Each sheet carried a pale border, but the middle remained empty. A price had been written on the first page in a firm, impatient hand.

The stallholder said it was a visitor's book that had never found any visitors. He sounded amused, as though the book had failed at a modest social duty. I imagined it lying open in a hallway, waiting through years of people who had forgotten their spectacles or preferred not to write.

A woman beside me asked whether she could use it for sketches. The stallholder nodded. Suddenly, I could see pictures filling the borders, and the blank pages no longer seemed to record an absence. They had become room for something that had not happened yet.

I put the book down. The woman continued looking at it while I moved towards the paperbacks. A few minutes later, I heard the stallholder tearing a piece of wrapping paper. I did not turn round to see which book he was wrapping.

How does the writer develop two different ways of seeing the blank book?