Windmills are machines, at their best when seen at work. A still photo can't show the work being done, but it can
suggest it - whereby the sails of the mill may appear blurred, showing they were in motion at the time the picture was taken.
This
picture of Jack and Jill is therefore a little unsettling - it
shows a blur to suggest motion - but unusually the foreground image of Jill is rock steady, whilst it is the background image of
the clouds that has moved and shows the blur. Technically this was achieved by using a neural density filter over the lens, so
as to cut down the light entering the camera, and hence to require a long exposure (13 seconds).
which includes a number of shots of Jack and Jill, plus some of Outwood windmill.