Michael Flowers from the Tolkien Society has provided me today with this interesting entry from the Evening Mail from 15 November 1820:
We never saw this wealthy neighbourhood more generally or more splendidly lighted up. The inhabitants seemed emulously to vie with each other in giving the best and most brilliant effect to the illumination. Paynter and Co. displayed a transparency of the Queen, drawn by four white coursers, in a triumphal car. In her hand she bore a scroll, with the words: "God defend my rights." The front of Saddlers'-hall presented the letters "C.R." beneath a triumphal arch in brilliant yellow lamps. The house of Mr. Tolkien was ornamented with a transparency representing the Thistle, the national emblem of Scotland; and, on a tablet near it was the inscription– "Scotia, the land of Wallace, Bruce, and Knox" – "Nemo me impune lacessit."
All this was on the occasion of the coronation of Caroline (Caroline of Brunswick), Queen of the United Kingdom as the wife of King George IV (she reigned from 29 January 1820 until her death in 1821). Michael Flowers described the events at Cheapside as "the sycophantic preparations". This is of course something many individuals and businesses did at the time.
"Mr Tolkien" was probably Charles Tolkien (born 1789), son of Daniel Tolkien (born 1746 in Gdańsk). His house was probably 60 Cheapside where Master Daniel Tolkien had his "Skinner and Furrier" shop.