I was very excited to see a pineapple plant and just purchased it. But now I’m questioning whether the pineapple is already dead. It looks very brown/black.
I would suggest that the fruit of this indoor plant has reached maturity and should be cut below the fruit and you can even try to eat it!
The rosette that formed that fruit will now begin to die - The Circle of Life etc, but as is the case of the same plant I was given to me for my birthday last week, it will reward you with new plantlets which in turn will grow and follow the same process.
Obviously, out in the wild, pineapples will grow much larger, but those which are grown specifically as more 'novelty' houseplants (which includes bromeliads that display the same process after flowering) rarely grow much bigger.
Ostensibly, you can also cut the fruit just below the leaves above the fruit and bury the base in substrate and in theory it will then root and in time produce another fruit etc but in the UK where I live it is a fools errand (at least for me lol having tried it many times before and it has always run to rot).
There is an alternative and more adventurous option and that would be to let the fruit stay in place and the long stem that holds it will eventually bend over, whence you carefully bury the pineapple fruit in a pot adjacent to the mother plant's pot and pin & cover it in substrate. In this method, the mother plant's dying leaves will direct some extra nutrient and water to the fruit top and the chances of root success of the fruit top may be improved. Of course, it WILL mean less resources will go into new plantlet growth from any new root nodes