As an aside - the London photos are surveillance, no? So that means that they are focused on watching a destination or a route to a destination.

Watching the road would not be very useful, as traffic cams are likely already available; and anyways, the utility of a camera focused on traffic (with the multitude of cars and insignificance of traffic in general) is not too high. Therefore I'd say it looks like these cameras are specifically made for pedestrian surveillance, on a path or destination.

There is no destination in the first street photos, but the Corinthian Hotel is definitely a destination.

So, if one assumes that the Hotel is the destination and the first street photos the path, I'd suggest that the path we are looking at here is the footpath between the offices of Parliament and the Hotel. The Hotel is so nice, and so close, that it likely figures as a prime location for foreign dignitaries or agents to stay when visiting Parliament. Just walk out and take a nice stroll up the street to get to Parliament, with a park to the side to boot.

If Q Team had indication to believe that a black hat was visiting Parliament with sensitive info, they would love this camera angle. That's what I think we've got here. Look at the pedestrians (like some are already), and look for potential timeline matches between POI London visits and scenery/other cues.