Pick One

Violet had lain three books down on her bed, a Thomas book, a book about Spot the puppy and a book about Elmo and his blanket.  She arranged them in a new row, next to each other.
She said to me, "Pick one."
I picked the Thomas one.
She said, "No.  Pick one."
I laughed in surprise that I could have picked the wrong one.  I picked the Spot book.
She said, "No," and pointed to the Elmo book.  "Can you pick this one?" she said.
I said, "Sure," and laughed again.  It kills me when she does an adult thing, but doesn't really understand the rules.