This is a bit of an enigmatic verse. The point of it is not about the structure of how angels are organized, but the purpose of what they are doing and what it means for us.
The angels are watching. They are in communion with God and they are observing the earth. They see us. They see Him. Like eyeballs at a tennis match, they are watching what we do, in awe of the way we exercise our opportunities. At the same time, they are seeing God. They see how delighted He is with us; how He beams over each of His children.
The angels are watching to see if we will take advantage of our unique opportunity as humans. Will we exercise faith? The ability to trust God without physically seeing Him. To believe without knowing. To value what is sometimes unseen and hoped for over and above what we can understand or control.
When we squander or inhibit this ability within one another, the angels see that too. And they see that God sees.
While we are here on this planet, we get the chance to trust God. And we get the chance to help others trust God as well. We get to exercise faith, as an individual and within a community.