Whoah, this is getting to be hard work. Fortunately Zechariah has pretty much no idea what he is seeing either. The angel is always saying “do you get it?” And he’s always “no”. Then it’s explained, but I still barely get it. I’ll guess, then research and see how close I was!
It’s a vision of the founding of the temple. The message is that laying one small foundation stone on one building may seem not much, but when it is part of the means of God’s grace it is a world event. So don’t despise the day of small things, because if it is a work of the Spirit, it’s an earth shaker!
Read a commentary, and yeah roughly there, minus much detail. The two who serve at the end of the chapter they say are prophet/king – spiritual leader; and priest – declarer of forgiveness. The roles were split at the time of Melchizedek, joined again in Christ.
So it is a huge encouragement to their work and ours on earth. Don’t be overwhelmed, live in the light service of the Lord (his yoke is easy!), and with the power of the spirit, not your own.