Consider Twain's description of the Grangerford's home. Huck is greatly impressed by the beauty of the house and the grandeur of its furnishings and goes to great lengths to describe them. "There was some books too, piled up perfectly exact, on each corner of the table." The books conveyed the impression of refinement and learning, but they were apparently never read, which was why they could be piled up so precisely. Twain is using irony to make fun of the excessive clutter that was showy but meaningless. Hyperbole comes out in the descriptions, too. Speaking of the clock on the mantel, Huck reports
when one of these peddlers had been along and scoured her up and got her in good shape, she would start in and strike a hundred and fifty before she got tuckered out.
Huck's reaction to the Sunday sermon is phrased in sarcastic terminology, as he reports all the positive reactions it was given and all the important topics it addressed but ends "it did seem to me to be one of the roughest Sundays I had run across yet."