Picture an approved gap. Your place stays yours. You step out of it for a stated length of time because someone with authority allowed it, and going back is part of the arrangement from the start.
English took furlough from Dutch verlof, which probably goes back to Middle Low German verlof, 'permission'. It is a doublet of leave, a word that likewise carries both 'go away' and 'time off'. The old idea of permission is still what holds the modern uses together.
furlough 借自荷蘭文 verlof，往前可能來自中古低地德文 verlōf，意思是「允許、准許」。它和英文的 leave 是同源的雙生詞，而 leave 同樣兼有「離開」和「休假」。「有人批准」這一層，正是今天各種用法共同的底。
Wiktionary entry for furlough, etymology_text supplied in this packet (source_ref kaikki:3f6f69a190036ae4:782339440:18774)
From the picture
公司叫你先別來上班
同樣是那段「被批准的空檔」，只是這次批准的理由是錢不夠，而且通常不給薪水。工作沒有被收走，這一點和核心畫面完全一致。
noun · C1
A period of time when a company or a government tells workers to stop working, usually without pay, because there is not enough money to pay them; the workers keep their jobs and are expected to come back.
無薪假；暫時停工
noun · C1
A period of leave when a soldier, or someone whose work keeps them in another country, is officially allowed to go back to their own country for a while before returning to duty.
返鄉休假；准假
noun · C1
A short period during which someone who is in prison is officially allowed to leave, for example to visit family or to attend a funeral, and must then return to the prison.
（受刑人的）短期外出假