The Throne Angels are the third Choir of Angels, the spiritual creatures that God has created.
When reading the Holy Scriptures we come to understand that there is an invisible established government in Heaven. And that God, the Creator of all things, visible and invisible, reigns above all.
Often you see the third choir of spiritual creatures portrayed when kneeling in adoration and holding a little throne in their hands.
According to St. Thomas Aquinas, these Angels have to ponder the disposition of Divine Judgements. This means it's them who carry out the divine justice of our Lord.
This is why you see them painted while holding the staff of authority in their hands, clothed like judges.
God tells us in His Holy Scriptures that all authorities here on earth have been established by Him; the same counts for the invisible authorities.
All creatures, visible or invisible, have been created by God to adore and serve Him.
God chose to form various choirs of angels to accomplished specific tasks on earth and in heaven. For this He provided these angelic beings with specific properties.
We understand that they can create, channel and collect incoming and outgoing positive energies. They are the ones who shine a light on all injustice. They do this to bring these injustices to our attention.
God uses them also to send healing energies to victims. Just like the Cherubim, they come the closest to spiritual perfection and they emanate the light of God with a goodness that is just like a mirror.
Despite all their sublime gifts, they are intensely humble. This makes it possible for them to administer God's Justice with a perfect objectivity. They can do this without any fear of falling into the vices of pride and ambition.
Indeed God's creation is immensely diverse. And to know that it was His will for us to be the Master Piece of His creation, makes us become humble and forever grateful!