The angel prophesies about Babylon falling, which here means being destroyed. It is spoken of as having already happened. This is common in prophecy. It emphasizes that the coming judgment will certainly happen. The angel also prophesies that the people will lament over Babylon falling. (See: [[rc://en/tw/dict/bible/kt/prophet]] and [[rc://en/tw/dict/bible/kt/judge]] and [[rc://en/ta/man/translate/writing-apocalypticwriting]])
Prophecy frequently uses metaphors. This chapter has a slightly different apocalyptic style than the Book of Revelation overall. (See: [[rc://en/ta/man/translate/figs-metaphor]])