Some people say Revelation is purely symbolic.
Some people say it is literal.
Personally I consider most of the images of Revelation open to a literal interpretation, i.e. it was literally what events on earth looked like from the vantage point of heaven to a human transported there (i.e. John).
John is in the third heaven where Paul went, the same place Moses saw from the mountain and others like Daniel and Isaiah also saw. He is in eternity looking down at events on earth occurring in time. There is bound, even for this reason alone, to be considerable differences between what he saw of the same events in comparison to someone viewing them from an earthly viewpoint and in time.
I also believe that he was looking at the spiritual rather than the physical bodies of each participant.
This should make the imagery in Revelation more easily understood (perhaps ….).
Here are some thoughts:
The sea is how time looks and it also gives a spiritual view of events on earth – c.f. Rev. 13, Daniel 7:2. All the images in Revelation to do with this earth and time arise from the Sea. In Chapter 13:1 we see a spiritual being (the dragon or Satan) standing on the shore of the Sea. Jesus is of course enthroned above the Sea, seated at the right hand of the Father.
Animals represent creatures/ corporations with no relationship with God.
Humans represent creatures/ corporations capable of a relationship with God.
Corporations in this sense are collectives of people with one spirit, e.g. nations, empires, etc.
When Revelation speaks of life and death it is normally spiritual life and death that is meant. Of course, this is far more important than physical life and death (see Matt. 5:29-30).
Revelation can be very hard to understand. John was in the spirit in eternity. Does Revelation make more sense if what John saw and describes are actually the spirits of nations, empires and kings and not physical views of those things? What if the sequence of events recorded in Revelation is not in time (where it is linear) but in eternity (the events happen more like a disk)?
In particular take note of Rev. 15:2 – those who can be seen rising up and standing on the Sea and praising God, I believe this is us the Church worshiping here and now.