Chapter 13 continues the revealing of the ways in which the invisible great red dragon, "that old serpent, called the Devil, and Satan" works his final deception upon humanity, in order to try to maintain his usurpation of the rightful rule of Christ. To fully grasp the meaning of only one half of one verse in that chapter, one would need to diligently study much more beside. Therefore, I will quote relevant bits from a 614-page book devoted to that.
The verse in question speaks of a symbolic "beast like a leopard", and it is the significance of the power, throne [or, seat] and authority given to it by the dragon that is sought. The dragon is Satan the Devil, as stated in paragraph one, and it is his power, his seat, and his authority that is given.
Chapter 13 reveals two global concepts. That evil adversary uses those powers or authorities that he is in control of to foist his last, and greatest deception over the whole world. Those two concepts are depicted as two beasts, the first arising out of the sea with seven heads, ten horns, upon which are ten crowns. Those heads have the name of blasphemy. This beast has some appearance as of a leopard.
The second beast comes out of the earth, having two horns like a lamb, speaking as a dragon, and "exercising all the power of the first beast before him, whose deadly wound was healed". The second beast is likewise used to deceive humanity.
A crucial difference between the beasts of Rev. ch. 13 and Daniel's visionary beasts is that, in Revelation, they are an amalgamation, not a succession. THE beast of Rev. ch. 13 is a composite. Daniel's series of beasts combine to give form to the beast of Revelation. As this book explains regarding this last-day composite, it has all the features of the Daniel beasts:
"...besides having features of its own, such a composite implies all
those powers envisaged in Daniel, but more. Here is the all-embracing
summation of the entire concept, whilst the successive beasts in Daniel
depicted manifestations of that concept for the succeeding times then
present. But the beast of Revelation 13 answers to time itself...
Now these visions are some six hundred and fifty years apart, yet in
so vast an interval everything that Daniel prophesied had come to
pass... John stands as it were on the edge of the world. He views time
as a whole, and perceives in visionary and symbolic form the
principles which hold good throughout time. Although Daniel saw one
beast rise after the other, John discerns all these beasts as being
various successive manifestations of but one. Here is the true vision
of the history of the world." The Revelation of Jesus Christ, John
Metcalfe, pp. 304-308, extracts,
http://www.johnmetcalfe/publishingtrust.co.uk/contact_us.htm
It is necessary to explain this first in order to grasp the awesome extent of the power, throne, and authority of this Revelation beast. The great red dragon is an invisible, evil spirit and no humans can see this. He has to remain invisible to perpetrate his dastardly deception, for if people saw him they would be so terrified and repulsed he would no longer be able to keep pulling their strings from his invisible kingdom of evil. Therefore, he continues to use earthly agencies of his making, Revelation chapter 13 giving the word-picture culmination of the final manifestation of the great red dragon's deceptive scheme.
It is the great red dragon itself that is the power, the throne, and the authority at work in the earthly concepts that it creates, in order to attract human adoration and obedience. People who fall for this concept are being controlled by the very power, throne and authority of this epitome of evil rebellion against God, the great red dragon.
The three adjectives used in Revelation 13 stress just how totally this 'beast' is his creation. We have been warned in the strongest possible terms to believe God's revealed warnings and to resist this global concept from Satan, that will deceive all but the elect. This triad of unholy power, throne, and authority stands in diametric opposition to God's holy power, holy throne, and holy authority. The book of Revelation keeps stressing God's power, throne and authority, whilst simultaneously warning us of the ultimate evil power, throne and authority of the great red dragon. They stand in opposition. That is what we are meant to grasp. My last quote from the book above is:
"The mind of the dragon is to gain the crown rights properly due to
Christ. He will have the crowns. In the graphic imagery of Revelation,
he will gain his end by the power of the beast, that is, the ten
crowned horns. This indicates complete power, as do seven heads
perfect intelligence, not in relation to heaven, but in relation to
the earth.
The beast [out of the sea] - an invisible figurative allusion - will
yet again reign completely with the name of blasphemy; that which is
set up against God: the blasphemy of world dominion forced by the
dragon through this - in fact - idealistic and invisible form, the
'beast'. Mankind as a whole remains - and will remain - wholly
oblivious to what actually takes place in the realm of that which is
invisible, spiritual, and visionary." (Ibid. p. 310)