The irony of rape cases
One of the worst parts of Vivian's aftermath is that ironically, as the victim of one of the most terrible, traumatic experiences the earth has to offer, has to suffer even further at the hands of the same victim, in front of her peers, in a court of law.
But rape is usually done without witnesses, and very often, a woman's decision to pursue justice also brings her a tremendous amount of trauma itself, and so Vivian has to withstand the humiliation of the defense attorneys and the unjust treatment continues.
The irony of hatred and evil
There are people who use their own suffering as license to intentionally mistreat others. This might seem logical at first glance, but actually, it's ironic. A person who is made to suffer is also especially able to empathize with others, but instead, Johnny uses his pain as an excuse to become evil. If anyone should know not to cause harm to others, it's people like Johnny who have already borne witness firsthand what mistreatment can do to someone. His story is a great explanation of why he should not rape. It is only hatred that causes someone to want to harm others.
The irony of art
Art is a wonderful tool for encoding experiences and emotions into digestible stories that other people can understand, but when the subject of the artwork is as traumatic and terrifying as Winnie Li's real life rape was, then it's no wonder the novel seems to fail at some of its assumed goals: entertainment, inspiration, etc.
No, in this case, the most appropriate way for Li to tell her experience is to be as blunt and straightforward as possible, not making use of certain tools.
This is clear in the plot structure. She didn't choose to encode her experience in some metaphor. She just wrote a book where a girl like her is brutally raped, like she was. The irony is that in this case, that might be the purist use of art available, but on its surface, it seems less like art and more like non-fiction.
The irony of post-trauma
If you've ever been extremely hungry, and you eat, you might say, "Thank God that's over with." But traumatic incidents break the brain, and it takes a long time to rebuild it. This means that for the worst kinds of experiences on earth, traumatic experiences, even when the moment ends, the emotional and psychological effects continue. It's like suffering agonizing hunger, and being able to eat, but not to feel full, and what Vivian is hungry for is peace-of-mind. PTSD makes that a very difficult prospect.
The irony of youth
There is a serious legal question about what to do with pathological or sociopathic children, and make no mistake, a 15 or 16 year old is different from an adult, scientifically speaking. But does that mean that he is less guilty? It certainly seems that in this case nothing should be permitted as evidence in his defense, since his actions are clearly indefensible. It's ironic that a grown woman would be raped by a youth, and the legal problem is paradoxical.