May I add a comment here?
Although photography is allowed onboard BA aircraft, please be considerate of others. I get countless complaints from other passengers who are sensitive to having their photograph taken by strangers. Also, I know crew do not like to be photographed/filmed without permission and they are well within their rights to approach someone who is taking footage of them and ask them to delete the pictures or film!
Just be careful and considerate of others keeping in mind that aircraft are small confined spaced.
However a photo out the window should not be an issue!!!