Here’s another phone box from when I was in London last November.

(Coordinates 51°51’46.4″N, 0°13’31.2″W.)
Here’s a bonus Street View image where you’re right up in the phone box’s face! I think the Street View car must have had to squeeze past quite closely to avoid the roadworks on the other side of the street.
Anyway, this box is typically well-kept for a London phone box. From the Street View image, I’m guessing that posters etc. are not allowed on the box even in the summer, but I bet it doesn’t stop people trying.
Another London phone box next week!