Time flew by playing this, loved it! Clues could be found in the most interesting places! A little over the half of the game, I too wasn't sure of the logic and kinda went with random selections (usually between 2-3 options). A walkthrough with the logic around each photo will be amazing to satisfy curiosity! I am also wondering where/if the names in green (students that disappeared) are used.
PS: I would definitely buy a full version of this (eg more levels of yearbook puzzles)!