It's imagery. But it's not somehow four witnesses, if that is what you are implying. It's two connected images detailing one concept, using words that invoke associations. Remember this is in spirit, and John is seeing what Zechariah also saw-- a golden lampstand with seven bowls that hold the oil from these two olive trees that supply them. There are not two candlesticks, rather two "pipes" that extend from these two olive trees which supply the olive oil from branches on the left and right side of the lampstand.
Whatever helps you envision it-- The text is describing the source of the oil (the anointing) that pours through these two witnesses, and though they are depicted as trees-- these trees are men.
“and said unto me, What seest thou? And I said, I have looked, and
behold a candlestick all of gold, with a bowl upon the top of it, and
his seven lamps thereon, and seven pipes to the seven lamps, which are upon the top thereof:
and two olive trees by it, one upon the right side of the bowl, and the other upon the left side thereof.”
Zechariah 4:2-3 KJV
“And I answered again, and said unto him,
What be these two olive branches which through the two golden pipes empty the golden oil out of themselves? Then said he,
These are the two anointed ones, that stand by the Lord of the whole earth.”
Zechariah 4:12, 14 KJV
“And as he prayed, the fashion of his countenance was altered, and his raiment was white and glistering. And,
behold, there talked with him
two men, which were Moses and Elijah: who appeared in glory, and
spake of his decease which he should accomplish at Jerusalem.”
Luke 9:29-31
“And I will give power unto my
two witnesses, and they shall prophesy a thousand two hundred and threescore days, clothed in sackcloth.
These are the two olive trees, and the two candlesticks standing before the God of the earth.
These have
power to shut heaven, that it rain not in the days of their prophecy:
and have
power over waters to turn them to blood, and to smite the earth with all plagues, as often as they will.”
Revelation 11:3-4, 6 KJV
“power to shut heaven, that it rain not in the days of their prophecy: “
“And I will give power unto
my two witnesses, and they shall prophesy a thousand two hundred and threescore days, ( 3 and a half years ) clothed in sackcloth.”
Revelation 11:3 KJV
“And
Elijah the Tishbite, who was of the inhabitants of Gilead, said unto Ahab, As the LORD God of Israel liveth, before
whom I stand, there shall not be dew nor rain these years, but according to my word.”
1 Kings 17:1 KJV
“
Elijah was a man subject to like passions as we are, and
he prayed earnestly that it might not rain: and
it rained not on the earth by the space of three years and six months.”
James 5:17 KJV
“power over waters to turn them to blood, and to smite the earth with all plagues”
of course Moses turned water to blood and set off plagues upon Egypt …..
moses gave the law which witnesses of Christ and Elijah represents the prophets who also witness of Christ
“And when they had appointed him a day, there came many to him into his lodging; to whom he
expounded and testified the kingdom of God, persuading them concerning Jesus, both out of the law of Moses, and out of the prophets, from morning till evening.”
Acts 28:23 KJV
“But now the righteousness of God without the law is manifested, being
witnessed by the law and the prophets;”
Romans 3:21 KJV
“Having therefore obtained help of God, I continue unto this day,
witnessing both to small and great,
saying none other things than those which the prophets and Moses did say should come:”
Acts 26:22 KJV
“Yea, and
all the prophets from Samuel and those that follow after, as many as have spoken, have likewise foretold of these days.”
Acts 3:24 KJV
“To him give
all the prophets witness, that through his name whosoever believeth in him shall receive remission of sins.”
Acts 10:43