Directives: come up with an image that would be easy to change and tweak around, it would also answer the British Council's general tone for all imagery. The hard bit here is that they don't have anything on neither iconography nor illustration in their branding (only photos could normally be used), so this is questionable if such approach will be approved. Among other considerations, it was decided to do it in black and white, and graphically simple, to oppose the photographic row.
