看著一道真的門
這就是核心畫面本身，沒有比喻：真的牆、真的門、真的一個人坐在旁邊。
noun · B2
A person whose job is to look after a gate: to open it, to close it, and to allow or refuse the people who want to go through.
守門人；看門的人
核心畫面
One way to hold gatekeeper: a long wall with exactly one opening in it, and one person sitting beside that opening. The wall does the real work of keeping people out; the person only has to sit there and say yes or no. That is the whole idea. Because there is no other way in, a small job at a narrow place turns into real power over everyone waiting outside.
gatekeeper 可以想成這樣一個畫面：一道很長的牆，上面只有一個開口，開口旁邊坐著一個人。真正擋住大家的是牆；…更多收起
gatekeeper 可以想成這樣一個畫面：一道很長的牆，上面只有一個開口，開口旁邊坐著一個人。真正擋住大家的是牆；那個人只要坐在那裡說可以或不可以。整個字的意思就在這裡。因為沒有別條路可以進去，一份看起來很小的工作，就變成了對門外所有人的實際權力。這道牆後來常常是看不見的。From the word’s history
Wiktionary gives the word as gate + keeper — literally the person who keeps (looks after) the gate. Both halves are still visible: the gate is the one narrow way in, and keeping it means deciding what happens at it.
Wiktionary 記這個字就是 gate（門）加 keeper（看守的人），字面上是「顧那道門的人」。兩半到今天都還看得見：gate 是唯一的窄口，keep 是在那個口上做決定。
Wiktionary (en) entry 'gatekeeper', packet source_ref kaikki:3f6f69a190036ae4:1236607328:22483
Two branches
看著一道看不見的門
牆和門拿掉，畫面剩下最重要的部分：只有一條路能過，而那條路上站著一個人。於是編輯、助理、考試、平台，都可以是 gatekeeper。
noun · B2
A person or group that controls who or what can get through to something: who is let in, who gets seen, or which ideas reach other people.
把關者；掌握門路的人