I was checking the gallery stuff right now. 10th one "Youll never be happy" refers to the Bittersweet End, and the 12th being "Blood is thicker than water" (referring to your mystery "friend") of the True End. Theyre supposed to be unlocked by getting these two endings, according to the code... But for some reason, its not doing that, and thats unfortunate because the pics in question are nice.
I'm quite confident that these are bugged. I also dont for example see the necklace and brochure in Abzi's date's item search. (I think the code doesnt call for the correct image/line)