Huck is entranced by the circus, considering it the most beautiful thing he's ever witnessed. He describes the costumes as those of queens, and remarks on the gracefulness of the performers, amazed at how their bodies move. So, it's clear that Huck appreciates beauty. The most telling reaction however, comes after the big climax of the circus. A man, obviously drunk, insisted on entering the ring and riding one of the performing horses. He does so, and as the horse runs, he sheds his clothing, becoming more graceful, revealing that he too is a performer. Huck understands that portion, but doesn't get that everyone in the circus is in on it.
Then the ringmaster he see how he had been fooled, and he was the sickest ringmaster you ever see, I reckon. Why, it was one of his own men! He had got up that joke all out of his own head, and never let on to nobody. Well, I felt sheepish enough to be took in so, but I wouldn't 'a' been in that ringmaster's place, not for a thousand dollars. I don't know; there may be bullier circuses than what that one was, but I never struck them yet. Anyways, it was plenty good enough for me; and wherever I run across it, it can have all of my custom every time.
So Huck feels the worst for the ringmaster, thinking he had been fooled by his own man. Huck himself has a level of gullibility, even though he is sharper than most people around him. He can still be fooled though.