Trabb’s boy’s assistance when Pip is kidnapped by Orlick is significant because it shows that Pip is no longer playing at being a gentleman; he is actually maturing into one. Ironically, he no longer has a gentleman’s money.
Dickens plays with two definitions of “gentleman” in Great Expectations. Definition 1: A gentleman has money, but is not necessarily a good person. Definition 2: A gentleman is a considerate and mature person. Pip does not like Trabb’s boy. In chapter 19, Trabb mocks Pip because he realizes that he is acting like a fool.
Mr. Trabb's boy was the most audacious boy in all that country-side. When I had entered he was sweeping the shop, and he had sweetened his labours by sweeping over me. He was still sweeping when I came out into the shop with Mr. Trabb, and he knocked the broom against all possible corners and obstacles, to express (as I understood it) equality with any blacksmith, alive or dead. (enotes etext p. 106)
Pip is offended by Trabb’s boy, and what he views as disrespect. He thinks Trabb’s boy should show him the respect his new station deserves. Yet in reality, his obsession with Trabb’s boy reveals that he realizes he has not achieved full gentleman status, mentally at least. His own insecurities fuel his anger.
By the time Pip has his near-deadly encounter with the viscous Orlick, many things have changed. Pip is now much more mature, and he is more interested in protecting Magwitch than maintaining his own status. He knows he will never be a gentleman now, and does not care.
When Trabb’s boy’s face is the first thing he sees, Pip is still surprised. Trabb’s boy is no longer mocking.
“I think he's all right!” said Trabb's boy, in a sober voice; “but ain't he just pale though!” (chapter 53, p. 290)
At this point Pip has almost died, and he, Herbert and Startop have a dangerous mission ahead- get Magwitch out of the country. It’s not fun and games for anyone, and Trabb’s boy knows it. He realizes that Pip is not a subject for ridicule. He is a gentleman in spirit, if no longer in name. He is the second definition of a gentleman.