Since this is the HN crowd, I'll explain it this way: if you assume your brain is a biological machine, what if you could decipher its firmware and hack into it? What if you could remotely exploit it and take over its sensory inputs? It's hard to say if a contact is "conscious" or not because "they" seem to have the power to exploit and control it, to communicate by sending symbolic language and imagery.

Contact is difficult to explain to this crowd; when I turn the tables and imagine someone explaining their experience to me, it would sound like something indistinguishable from magic. Something so unbelievable that you would immediately discount it and look for alternate explanations, or question the person's sanity.