This time, Allah uses a nominal sentence as opposed to the previous verse. This verse describes their constant state, while the previous verse describes the action that is repeated on them. They will never be absent from it, ever, at any given point in time. While they are inside it - which they will be for every single moment for eternity they will be repeatedly tortured and punished inside it.
Never from it, will they be absent
This time, Allah uses a nominal sentence as opposed to the previous verse. This verse describes their constant state, while the previous verse describes the action that is repeated on them. They will never be absent from it, ever, at any given point in time. While they are inside it - which they will be for every single moment for eternity they will be repeatedly tortured and punished inside it.