In photography, a triptych is a set of three photographs that are intended to be displayed or viewed together as a single work. The three images are usually related thematically, visually, or narratively, and they often have the same aspect ratio or are printed at the same size so they can be hung side-by-side or in another arrangement (e.g., one above and two below).
I think, 3 photographs are the minimum required for our brain to weave a story.