人或東西往後退
這一組就是核心畫面的字面版：真的有東西在空間上往後移動。
noun · B2
The act of moving soldiers back out of an area where they have been fighting, so that they are no longer in that place.
撤軍／撤離
核心畫面
Picture something that has been moving forward, and then a hand draws it back along the same line. It has not vanished and it has not broken — it has simply gone back a stretch of the way it came. What gets drawn back can be soldiers on a map, a plane at a gate, a person's involvement in a plan, or a number on a chart.
pullback 可以想成這樣一個畫面：一樣東西本來一直往前，然後有人把它沿著原路往回拉了一段。它沒有消失，也沒有斷…更多收起
pullback 可以想成這樣一個畫面：一樣東西本來一直往前，然後有人把它沿著原路往回拉了一段。它沒有消失，也沒有斷掉，只是退回去一點。被拉回來的可以是地圖上的部隊、停在登機門的飛機、一個人投入在計畫裡的力氣，也可以是圖表上一路往上的數字。From the word’s history
Wiktionary records pullback as deverbal from the phrasal verb pull back, so the noun still carries that action.
Wiktionary 記載 pullback 是由動詞片語 pull back 直接變成的名詞，所以「往回拉」這個動作一直留在字裡面。
Wiktionary (kaikki extract, packet field etymology_text: “Deverbal from pull back.”)
Two branches
數字往回掉一段
把核心畫面裡那條路換成圖表上的曲線，往回拉的就不是人，而是數字。
noun · B2
A fall in the value, amount, or level of something, especially after a time when it had been going up. It usually means a fairly small drop that people expect will not last.
回檔／回落