With the recent surge of mystery games with unique resolution mechanics, I think a full game focusing on compiling evidence from different photos could make for an incredible experience. The idea of comparing details from multiple shots and drawing conclusions really appeals to me.
For this iteration, I felt that the clues given were somewhat lacking, and I was fully defeated by the kitchen photo. I missed a conversation that appeared to the right of the stairs at first, and the limit of clicks per attempt made the process of trying to figure out what I was looking for, being forced out, and having to leave and come back to trigger it again rather tedious. I can't ask for a hint as it would spoil it for others, but I hope someone posts a playthrough or something for those of us who didn't make it to the end!
That said, I still love the concept, and I'm looking forward to whatever project you follow this up with!