* A reference to the banality of evil: The author might be drawing a comparison between some seemingly mundane action or inaction within the school or classroom and Eichmann's role in organizing the Holocaust. This would be a strong and potentially provocative statement suggesting a lack of moral awareness or responsibility.
* A historical or philosophical point: The letter might be discussing a historical event, ethical dilemma, or philosophical concept related to Eichmann's trial and the nature of evil.
* An inappropriate or provocative attempt at shock value: The mention of Eichmann could be an attempt to gain attention or be deliberately unsettling.
Without the context of the letter itself, it's impossible to say definitively what the author intends. However, it's safe to assume it's a deliberate and significant inclusion meant to convey a specific, likely critical, message.