Prior to Sunday, they had all been dark silhouette images, of a goat, elephants, monkeys, a wolf, pelicans and a cat.
But the newest offering appears to have been made using translucent spray paint on the sentry box’s glass windows, turning it into what looks like a giant fish tank.
Two police officers could be seen examining the design and taking pictures of it on Sunday.
“We are aware of criminal damage to a City of London Police box in Ludgate Hill,” detective chief inspector Andy Spooner said in a statement.
He noted the police force were “liaising” with the local authority who own the sentry box.
