derxa The picture will have been purchased (in license) from a picture agency, I should think.
The picture editor will have emailed the agency asking for something to go with the story, the agency person who deals with their account at the picture selection level will have sent a selection over (by email) and then the picture editor selected their favourite.
Alternatively, the picture editor may have simply used access to an on-line bank of stock photos (access purchased in bulk, annually) and just chosen one that seemed to convey the content of the story.
Newspapers just don't have the resources for an actual photographer to go off and take a picture for little stories like this. I don't think even local newspapers do these days.
But you could try writing a letter to the editor: 'Dear Madam/Sir, My attention was drawn to the photograph accompanying your story on deprivation and education in Thanet. I feel I must inform you that this photograph did not, in fact, portray children in Thanet ...'
I'm sure it will result in an email exchange between the picture desk and the picture agency.