This is her picture as she was:It seems a thing to wonder on,As though mine image in the glassShould tarry when myself am gone.~Dante Gabriel Rossetti
When is it Picture Perfect? How to photograph great portraits
It could be a gesture, or a facial expression that grabs you.
Or maybe a particular tilt of the head makes you look twice and think, “this could be a good shot”. Often I don’t see the greatness of a portrait until later when editing.