The Journal is where you can unlock more details about the story. After finding all three clues in the five hidden object scenes, you will see a notification on your Journal icon. When you click or tap on it, you will be asked to assemble a puzzle. Once completed, you will receive a gift and an additional story about the chapter.
To be able to open your Journal, simply tap on the book icon at the bottom of your screen.
For Computer Users:
To open your Journal, click on the book icon at the bottom right of the screen, above the Play icon.