掀開蓋子看到的細節
這一支就是核心畫面本身：那些小零件，屬於做這一行的人。
noun · C1
The small, detailed parts of how something is done or how a system works — the parts that mostly matter to the people who do that work. Almost always used in the plural: the technicalities.
細節；技術層面的細節
核心畫面
One way to hold technicality: take the cover off a machine and look at the small pieces inside. Those pieces are real and they do the work, but they are not what the machine is for, and most people never look at them. The word names one of those small inside pieces — and the interesting part is what happens when a small piece turns out to decide everything.
可以想成把一台機器的外殼掀開，看見裡面那些小零件。那些零件是真的在運作，但它們不是這台機器的目的，大部分人一輩子也不…更多收起
可以想成把一台機器的外殼掀開，看見裡面那些小零件。那些零件是真的在運作，但它們不是這台機器的目的，大部分人一輩子也不會去看。technicality 指的就是其中一個小零件。有趣的地方在後面：當其中一個小零件突然決定了整件事的結果，這個字就換了一種味道。From the word’s history
From technical + -ity, the suffix that turns an adjective into a noun.
來源可以想成 technical 加上 -ity。-ity 是把形容詞變成名詞的字尾，像 real→reality、able→ability。所以字面就是「屬於內行那一塊的東西」，也就是外行人不會去看的那些小零件。
Wiktionary entry for technicality (kaikki extract, source_ref kaikki:3f6f69a190036ae4:547679742): "From technical + -ity."
Two branches
規則裡的小零件，卻決定了結果
一樣是小零件，但這次裝在法律或規則這台機器裡；零件沒變大，它的後果卻變得很大。
noun · C1
A small point in a law or in a set of rules that decides what happens, even when the result feels unfair or has nothing to do with the real question.
（法規上的）技術性細節、小條文