A series of photographs spanning 60-odd years should reveal something about the subject, though the pitfalls of interpretation of expression and posture (etc.) are obvious. Consider this set of my father's mother Mell Eastman Blackmer (1876-1961). What can we read from them, or into them?
I have few memories of Mell --a few visits in the Home where she lived for the last 10 years of her life, one or maybe two Christmases at our house in Cambridge (probably in the late 1940s), a dinner in a restaurant sometime in the early 1950s. But no clear memories of what she was like. Most of what I "know" about her I learned or inferred long after her death, partly from family papers that are more eloquent for what they don't say than for what they reveal. My siblings (being considerably older than I) can probably shed some light on what she was like, and perhaps on the questiuons of why.
The pictures (and especially those from the last 50 years of her life) don't show a happy person. Her marriage to my grandfather was pretty rocky in its last 25 years (he died in 1936), probably due to his philandering. I suspect that none of the story is very simple, and nobody now alive knows what really happened.