Looking back now, 20 years after Neel's death, it is possible to see how she took a quintessentially bourgeois form - the portrait - and radically transformed it, while making the innate constraints of portraiture work for her.
He pushed his own form, the studio portrait, to extremes, exaggerating its basic components in ways that make us more aware of them: the trust that must exist between photographer and subject; the split-second "performance" that any still camera captures; the uncontrollable revelations of character; the way we all try to rise, as it were, to the occasion of a photograph.
8) Craters in Peru, making a 16,000 mile chain across the Andes, are believed by some scientists to form the self-portrait of a pre-Columbian extraterrestrial.
Strictly speaking, the modern-day selfie is a digital affair, but it's a novel iteration of an old form: the self-portrait (a friend on Twitter joked, "was Lascaux the first selfie?").
Nevertheless, for someone so frequently photographed, so frequently interviewed, and so practised at those forms as Jerry, the portrait sitting reveals things that no other situation could.
Several examples in the form of portrait heads are the first thing you see when you step off the elevator on the Whitney's fourth floor.
The films form a portrait of the distinguished poet, translator, critic and Brown University professor Edwin Honig — who was my cousin, friend and mentor — and his journey through the depths of Alzheimer's disease.
After realizing the difference was a lifetime spent working with sugar, he used the glittering grains to draw and form the children's portraits on black paper, and photographed the results.
But like many other art forms, the self-portrait has become more conceptual.
The portraits form the core of "Who Am I? Remembering the Dead Through Facial Reconstruction," the newest exhibition on display at the Johns Hopkins University Archaeological Museum.
It is just that the form their portrait takes, as it provides an alternative reading to the topic.
