The plaque inside the tree-themed box in Specter Valley is supposed to read "The goddess Flora handpicks the Guardians for her flowers. Their names will forever be etched in history." However, the actual text on the plaque is a bible verse from Matthew 7:24-27. It reads, "The rain fell, the streams rose, and the winds blew and beat against that house; but it did not fall, because it was founded on the rock."
Queen Violante's Tombstone is likely the Popup Note that causes the glitch that prevents players from unlocking the Popup Note Achievement. Because the tombstone appears differently in the game than the Popup Note itself appears in the Bonus Content images, the game never registers this Popup Note as being viewed in the game, and therefore the Achievement is never earned.
Depending on the computer and the item to read, the text would sometimes not appear. So far, only in MAC like computers has this effect.