It is fairly easy to pinpoint when this photograph was taken. There has been a lot of construction at this intersection in London over the last few years (A3211 near Northumberland). The CC tv camera this was taken from is probably at the end/top of the pedestrian bridge. Photograph appears to be taken in the late fall of 2015 given the trees, but from my research I can only pin it down to about a 6 month window. Another good question might be where were they heading and who were they meeting walking westward at that spot. Perhaps the national liberal club? Who knows, but that would be ironic…