Grammar of verb + noun + から

Question

I just read this question but was confused by a different aspect of the example sentence:

牛乳を飲み終わった人から、紙パックを自分の番号のケースに戻して席に着くように。

The question's answer is perfectly clear about the meaning, but I don't understand how the grammar of the part in bold works. When I see から I think of either 'from', 'because' or (if it's て-form) 'after'. None of these seem to work.

On it's own, the first clause (to me) reads

from the person who has finished drinking milk

but such a translation clearly doesn't fit with the rest of the sentence.

Is it a geneal rule that

verb-past + noun + から = as noun does verb

What about the tense/aspect of the verb? Some more examples would also be appreciated.

Answer 1

According to 明鏡国語辞典:

から
🈩〘格助詞〙
❼ 順序を表す。「好きなものから食べる」「子供から診察する」

And デジタル大辞泉:

1⃣［格助］
５ 動作・作用の開始順序や発端を示す。「先着の人から入場してください」

I think the から indicates the starting point of order, meaning 「～～から順番に」「～～から順に」, "starting from~~, in order from~~".

「牛乳を飲み終わった人から」≂「牛乳を飲み終わった人から順に」
"Starting from the person who has finished drinking milk, do ~~ in turn", hence the translation "As you finish drinking the milk, take turns in..."

I hope this makes sense.