4 ideas
In Genoa and Rome the Quaker City passengers named every local guide 'Ferguson' and met each treasure with feigned stupidity. Shown a Columbus autograph letter or an Egyptian mummy, they asked only 'Is he dead?' or asked whether the man was a friend of Columbus's. The guides' rehearsed displays of awe had nothing to act on, and the tourists turned the power relationship between guide and visitor upside down.
Demand from pilgrims produces the relics, and each shrine's income depends on its own authenticity claim. So the sum of relics exposes the fraud that no single shrine will admit.
Tourists arrive with feelings already set by guidebooks and earlier travel writers, so they report the emotions they were told to have and not what they see. Twain tests the prescribed raptures against the plain facts: the Sea of Galilee is small, Palestine is barren, and famous Old Master paintings are faded and cracked. Seeing honestly means noticing the gap between the reverence you were given and the object in front of you.
Guides, relic sellers, hotel keepers and shrine custodians work as one connected economy, built to turn the visitor's wish for meaningful experience into money. The tourists are not only victims. They join in by collecting, chipping pieces off monuments, and buying the story they came for. Each role props up the others, so the absurdity comes from the whole structure and not from individual cheats.