Question

There are many ironies in Chapter 22. Atticus loses, but the African American community showers him with gifts. Bob Ewell wins the court decision, but vows to get Atticus if it takes the rest of his life. Dill wants to be a clown, but a clown that laughs at the crowd. Choose one and explain its significance.
I understand the irony involving Atticus but I could use an explanation about how the other two are ironic.

Answer 1

Atticus loses, but the African American community showers him with gifts.
This is ironic because we do not normally give the loser gifts. In this case the African American community are giving gifts to Atticus because of the way he stood up for Tom Robinson. He made sure that the truth came out and treated the African American community with respect. 

Bob Ewell wins the court decision, but vows to get Atticus if it takes the rest of his life.
This is ironic because the winner is not expected to get revenge on the loser - he won! However, even though Bob Ewell wins the court decision he feels disrespected by Atticus. By revealing the possible truth of his violence towards Mayella and showing him to be a liar, Atticus shows Bob Ewell to be a bad person even though he is not on trial. This foreshadows the events that happen at the end of the book.

Dill wants to be a clown, but a clown that laughs at the crowd. 
This is ironic because clown is not the person who laughs at the crowd. The crowd laughs at the clown. Jem points this out and says, "You go it backwards...Clowns are sad, it’s folks that laugh at them." This further shows Dill's characterization.