Sherlock Holmes Chapter One

I believe this is story related, as I don't think you can progress during 'Ghosts of the Past' without doing this. Once you've reconstructed the scene during this prologue main story case, you'll have to go to room 226. Outside, you'll see two maid conversing, and will see an ear symbol. Click A, and you can start eavedropping on them. The idea is to disregard irrelevant information and select the 3 relevant snippets to unlock the gossip, although you can brute force your way through this minigame if you so choose.

If for whatever reason it is possible to miss this eavesdropping opportunity, you will need to eavesdrop countless time to unlock and/or complete a bunch of side cases, so this is bound to unlock at some point during your time completing this game.