It was painted to celebrate the ICC world cup cricket, the wording on it says,
The highest ODI total in History was hit by England at Trent Bridge in 1018 as they scored 481/6 against Australia
This postbox has been specially decorated to celebrate the ICC Men’s Cricket World Cup 2019 and the quintessentially British game of cricket.
Nottingham-born Stuart Board took a stunning 8/15 on his home ground during the 2015 Ashes
NOTTINGHAM TRENT BRIDGE
Now we have won the cup in each city where matches were played a postbox is to be painted white,