Most, if not all schools nowadays have an annual school photo
day. It probably started in the days before every home had
a camera and would provide proof - if any were needed - that
a) you had a child and b) that child had an education. This
in itself was mostly harmless. The trouble with this practice
and this particular day in the school year is that the product
can haunt you for the rest of your life.
This is the one day when the school invites a professional
photographer onto the premises in order to capture your image
for posterity. The photographs are generally taken individually,
but most sessions will include a group photograph of the entire
class. They may also include family portraits where siblings
(including pre-schoolers) can attend to be photographed. A
rarer sight today is the photograph of the entire school,
but they do still exist.