A not so familiar scene in Revelation

Below Satan, there are 2 beasts. One emerged from the sea. There was a 666 as a code to represent the identity of this beast. The other beast came from the land. It served under the beast from the sea. It deceived the peoples, made many people on earth worship the first beast. It marked the number of the beast on their right hands or foreheads (Revelation 13:12-16).
Then the focus panned to Mount Zion where the Lamb stood with 144,000 pure souls who were chaste. They sang a new song before God, the 4 living creatures and the 24 elders (Revelation 14:1-4).
Then 3 angels appeared one after another. The first one had a gospel to proclaim. He called people to fear God and worship Him (Revelation 16:7).
The second angel announced the fall of Babylon which is believed to be the codename of Rome (Revelation 14:8).
The third angel announced judgment on those who had worshipped the beast. These people would suffer God's wrath. What is worse, they had no rest (Revelation 14:10-11). This little circumstantial evidence suggests that the author of Revelation might be a slave, working under the sun without rest.
Later, the author saw a white cloud and a son of man holding a sharp sickle. An angel came out from the Temple and called him to reap the earth (Revelation 14:14-16).
And another angel came out of the temple in heaven, and he too had a sharp sickle (Revelation 4:17).
Yet another angel came and called the earlier angel to reap the vine from the earth. The vine was thrown into the wine-press of God's wrath.
and the wine press was trodden outside the city, and blood flowed from the wine press, as high as a horse's bridle, for one thousand six hundred stadia (Revelation 14:20).
What is it that shows his determination to love?
Why were there 144000 saints singing a new song to God?
Why does the angel enjoy the same status like the son of man?
In short, what does this picture symbolize?

My Lord, I have not loved You enough. There is still too much arrogance in me, especially towards people in power. Make me a humble and generous heart to serve You. Amen.