Final answer:
The author uses indirect characterization to portray Smiley as a sly, boastful, and risk-taking character who is confident in his frog's ability to outjump others.
Step-by-step explanation:
The kind of characterization the author is using for Smiley in this passage is indirect characterization. Instead of directly stating traits about Smiley, Mark Twain, the author, reveals aspects of Smiley's character through his actions, speech, and interactions with other characters.
We learn that Smiley is crafty, boastful about his frog's abilities, and willing to bet money on the frog's jumping prowess. He speaks in a nonchalant manner but is clearly confident in his frog, suggesting he is also a sly and perhaps deceptive character. The detail that he's willing to bet a significant amount on the frog's jumping ability demonstrates his confidence and willingness to take risks.