How does Mark Twain use imagery in The Celebrated Jumping Frog of Calavaras County?

Examples of Imagery:

“I noticed that he was fat and bald-headed, and had an expression of winning gentleness and simplicity upon his tranquil countenance.”

“They used to give her two or three hundred yards, start, and then pass her under way; but always at the fag end of the race she'd get excited and desperate like, and come cavorting and straddling up, and scattering her legs around limber, sometimes in the air, and sometimes out to one side among the fences, and kicking up m-o-r-e dust and raising m-o-r-e racket with her coughing and sneezing and blowing her nose-and always fetch up at the stand just about a neck ahead as near as you could cipher it down.”