How do you solve the second puzzle in Episode 2 [to find something to spoil Betty's image]?

After you've solved the first diary page, go to the gallery and tap 'hidden images.' Hit the top left square, then the square in the top middle, then middle of the grid, then top right, the middle right, then bottom right, bottom middle, bottom left, then middle left. You should've then filled in the entire grid. Tap on the image of Betty and share it to her through the messages app.