I put photos in my log book. To date I have only put photos of aircraft in them; I am on my fourth log book, and I only put the photos in once I have started on the new book.
Personally I don't want photos of people in my logbook, or airports etc, but don't think it would matter if it was relevant i.e you standing next to the instructor who sent you on your first solo with the aircraft in the background.
Logbooks are legal documents and nowhere in the law does it say it must not have photos in them.
As far as what an interviewer or organisation might think, I don't know. But again I don't think it would not be a deal breaker or maker in an interview.
Craven