In the Ancient World, the Eagle was associated with Zeus, the king of the Gods, and also with royalty. Here the eagle represents a special, royal messenger from God, The Theotokos. She bears a message of warning for the events that are to come. We will do wise to compare this message (Woe, woe, woe, to the inhabitants of the earth by reason of the other voices of the trumpet of the three angels, which are yet to sound!) to those delivered by the holy mother to the seers of this century.

The break in the text indicates a time shift. The first four angels were concerned with events that happen simultaneously along with the great earthquake. The next angels will present a different time sequence.  See my discussion on prophecy for an explanation of this shift.