The living Jesus, who has known life in the world, will be the judge of worldly people. No details are given here about the nature of that judgement, but something like the judgement of The King in Matthew 25 is often assumed.
There is a whole industry in the US based on images of the last judgement from St. Paul and the book of The Revelation, all of which mistakes eschatological events for historical ones. The judgement of the living and the dead does not take place in our space/time continuum; it happens in God, and can only be asserted as prophecy or vision. It expresses the faith that our universe does not have the last word on the story of creation. The brief mention here affirms that faith as part of the truth of God. I am happy to go along with that.
The most stark images of judgement are attributed in the gospels to Jesus himself, and therefore deserve respect. In the story of the sheep and the goats, I like to think that the line between them runs through each and every person, rather than dividing one from another. After all it is a story. And I look forward to being judged; As in any test, I would like to know my score. An objective estimate of my attempt at goodness would be helpful. And I would like to be finally rid of the bits of me that are “goat”; I’m happy to surrender them to the fire. And if Jesus is in charge of this process, I can trust it will be done in love.
Are there people who are all goat? If so, they may be complete goners, but the purpose of God’s judgement is to rescue all the goodness of persons by separating it from all the evil. in the classic medieval view of judgement, as in the Divina Comedia, I cannot see the point of Hell. It does nothing that a properly organised Purgatory could not do.