Much like other games in the series, this is because instead of solving the «Hidden Picture» puzzles, there is an option to switching them out for Mahjong games. (darkstation.com)
You are presented with a chapter of the story then are asked to play a game of Mahjong Solitaire to advance the story. (playstationlifestyle.net)
And believe it or not, there's now even a Halloween version of Mahjong Solitaire. (beyond-black-friday.com)