It can be really annoying to have photos and not be able to find out who the people are. Some years ago a photo was unearthed by a 'half-cousin' (we share the same grandmother, but not the same grandfather), and the likeness to our grandmother was so strong, we assumed that it had to be our g. grandmother. A couple of years later I posted the picture in this forum, and I found out that we had guessed wrong, because the date of the photo made it impossible for it to be her. So, we're still no nearer in finding out who the mystery group were !
