Thank you for this original post, Gem. My first reaction was to think about it. Assume I could be "smart" and say it was our cosmic essence, and go on to describe it in the hopes of being praised for accuracy.
And then I realized, perhaps the question wasn't meant to be answered. A practice for consciousness instead, presented as a means to spark a connection into the sensation that you mentioned in a following post; about being left in a place - a void, if you would, that is both nothing and everything - full of possibility of form or non-form. Perhaps this was what you meant, or maybe not. But regardless, thank you for presenting the scenario.
"You work so hard to fix yourself, but maybe what you need isn't another tactic, another book, another five-step plan. Maybe, you don't need to be fixed. Maybe, what's really holding you back is the idea that you need to be fixed."
- Vironika Tugaleva