But what does it take for one of these to be true?
Consider the second.
To work out whether it's true we have to apply the same procedure again.
The first step is to give everything a name, but since everything already has a name there's nothing we need to do.
Then we make new sentences by removing an existential quantifier and replacing the variable with each name in turn.
This gives us these new sentences, Above(b,a) and Above(b,b)
Now if either of these are true, then so is the sentence we started with, ∃y Above(b,y).