The writer makes a comparison between Queen Elizabeth and Harris, how does it add humor to the story?

Harris, like Queen Elizabeth was fond of public houses. None-the-less, she is credited with having visited most every establishment located along their route. This causes J to muse about how many signs would appear if Harris were to die a great man..... he alludes to the placed Harris had been "thrown out of", which brings a bit of humor to his musings. 

I mused on Kingston, or “Kyningestun,” as it was once called in the days when Saxon “kinges” were crowned there.  Great Cæsar crossed the river there, and the Roman legions camped upon its sloping uplands.  Cæsar, like, in later years, Elizabeth, seems to have stopped everywhere: only he was more respectable than good Queen Bess; he didn’t put up at the public-houses.

She was nuts on public-houses, was England’s Virgin Queen.  There’s scarcely a pub. of any attractions within ten miles of London that she does not seem to have looked in at, or stopped at, or slept at, some time or other.  I wonder now, supposing Harris, say, turned over a new leaf, and became a great and good man, and got to be Prime Minister, and died, if they would put up signs over the public-houses that he had patronised: “Harris had a glass of bitter in this house;” “Harris had two of Scotch cold here in the summer of ’88;” “Harris was chucked from here in December, 1886.”