The definition of image is:
an image, figure, likeness
used of the moral likeness of renewed men to God
one in whom the likeness of any one is seen
An example in English is when we say something like, You are the spitting image of your father.
So when Rev. 13 talks about the second beast is built in the image of the first, it means they are just alike.
Rev. 17:8 that describes the beast that was, and is not, and yet is, it's talking about past present and future beast kingdoms. In Rev. 17:10 +11 it is saying there are 8 different beast kingdoms that began way back in Egypt, and continues in various incarnations to the last days. The 8th is of the seven and goes into perdition.
Egypt, Assyria, Babylon, Medo-Persia, Greece, Rome, Islam, Islam revived from a head wound.
The first five have "fallen" by the time John wrote Revelation,
Rome "is" at the time of Revelation's writing,
Islam was "not yet", and "yet is" now.
That makes 8. The last is of the 7, all kingdoms out of the Middle East, all similar.
We know this because of Neb's dream about the statue that Daniel interpreted.
So when you read Rev. 13, those two beasts are the final 2 which are like the bear, the lion, and the leopard kingdoms, but the last beast acts and does exactly like the one before him who had a deadly head wound. They are the exact image of each other, Islam then, and Islam now, and it stands where it ought not, on the temple mount, claiming to be God until the end is poured out. Islam now speaks via the Koran, and Islam now causes people to worship the image of the beast or be killed.