Sequence of Activities:

1. 10 minutes or as much time as needed (do in advance of lesson): Choose a personal photo on your phone or social media or a physical photo from your collection that evokes a story or memory. If you don't have the actual photo but can remember it, you can also examine what you remember in your mind. If you don't have a picture but you do clearly remember some person, place, or thing that you can take a mental picture of in your mind, then look at that.
2. 10 minutes: Then, write about the image from the third person point of view. Describe the scene with enough objective, factual detail that a person who could not see the picture could nonetheless "picture it" in their mind. Be as detailed as possible. This works best if you choose details that also convey some meaningful emotional resonance, even as you describe them more objectively, rather than noting that there’s a beige wall in the background but that detail isn’t really that important to the story. Write for 10 minutes.
3.  7 minutes: Choose a pivot line, something mysterious like, "What people didn't know by looking at this picture was..." or "Something that nobody would have imagined would happen next was..." Or "No one could predict that ten years from then..." Complete the sentence by sharing the narrative, insight or backstory about what happened later or what was happening at the same time the picture was taken that reveals more of the emotion behind the experience. Reveal some of that subjective, “insider” information about what was being felt or thought by characters in the scene. Write for 7 minutes.
4. Combine the two parts from steps 2 and 3 as one piece.
5. 17 minutes each: Repeat the process of steps 2-3 for multiple photographs, possibly over multiple periods or as homework.  
6. Unify all the different pairs of writings about photos together with additional words or phrases to connect the sections into a story or assemble the pieces as separate sections through juxtaposition or section breaks, but as part of one longer piece of writing.

Extension: As a separate activity, create a slideshow to assemble each of the images into one sequence. There are countless other lessons about digital storytelling available on the web, but some digital stories can begin as a slideshow paired with a script to accompany telling about each photo, which is read aloud and audio recorded. This lesson could be a jumping off point for creating a script for a digital story.

Further extension: This process could be repeated or altered for a fiction writing activity by using images that are not from one’s personal life.