This photo seems to be taken from a bookworm’s study room. Everything is in perfect order, but one thing is unusual. Can you spot it?

The photo features some books placed on a table inline whereas one book is placed on the other side. It seems that the reader has just paused reading and is about to read it again. So he/she might have left a bookmark inside the book. Moreover, a flower pot and a painting are also present on the table.

However, something unusual can be noticed. Can you find it?

In a book, the bookmarker is typically placed on the top side whereas it is placed at the bottom.