Picture someone calling a group out one by one and standing them in a row so that you can look along the whole set in one go. What matters is not who is first but that the row is closed: these are the ones, they are in this order, and you can see all of them at once. Every use of line-up is that row. Sometimes the row is real people standing still; sometimes the row is on paper, and what is lined up are players, performers or programmes.
From the word’s history
The noun is formed straight from the phrasal verb line up, 'to stand in a row' (the source entry records it as deverbal from line up). So the picture inside the word is the action that made it: people were lined up, and the result of that action became a thing you can name, announce and argue about.
這個名詞直接從動詞片語 line up（排成一排）變來的（來源條目寫 Deverbal from line up）。所以字裡面裝的就是那個動作本身：本來是「把人排成一排」，後來「排出來的這一組」變成一個可以講、可以公布、可以評價的東西。
Wiktionary 'line-up' (noun) entry supplied in this packet — etymology_text: 'Deverbal from line up.'; source_ref kaikki:3f6f69a190036ae4:1946361438:1770
登入就可以看每一支怎麼連回核心畫面。