When I initially saw this it seemed to me to be a picture of a group of people on a beach somewhere making a movie. When I zoomed into the group, I could see lights set up and there seemed to be a smaller group in front of the huts with a large movie camera.
Subsequent to publishing this picture my Cousin found a reference to a film called Barnacle Bill which was made in 1957 and featured some filming on Hunstanton beach. It seems this picture was taken by an onlooker as that film was being made.
It is a red border, Kodachrome slide which fits in with the date of around 1957.
Beach Date Picture Taken: