In a moment of dramatic irony, John Canty’s band of outlaws mocks Edward for his offer to pardon Yokel with his authority as King:
“Long live Foo Foo the First, King of the Mooncalves!” followed by hootings, catcalls, and peals of laughter.
“Hale him forth, and crown him!”
“Robe him!”
“Scepter him!”
“Throne him!”
[...] almost before the poor little victim could draw a breath he was crowned with a tin basin, robed in a tattered blanket, throned upon a barrel, and sceptered with the tinker’s soldering iron.
It is no surprise that the thieves believe Edward to be insane. Though he claims to be royalty, he appears to be a totally average boy. But the irony is that Edward is actually the King and can pardon them of their crimes. In their ignorance, the thieves mock Edward mercilessly for his claims and so actually act against their own best interest, given his status.
The dramatic irony in this scene is not only funny, it also underscores the core theme of appearances vs. reality in The Prince and the Pauper. It is only Edward’s appearance, now tattered and dirty, that convinces these men that he is not a king. His manner of speaking, personality, and behavior haven’t changed at all. The judgment these people have made based on his looks alone has actually put them in danger, because Edward is (technically) the absolute monarch of the state, and can do anything he likes to them.
This scene also contains situational irony, as Edward has been raised to believe he and his father are adored by most people. When he announces his title to the thieves, he expects support and love from his subjects, only to receive scorn and mockery. In this section, and across Chapter 17, the monarchy and the law are mocked by the thieves and beggars, who have been victims of the injustice of both.
