Hi Fred /Dannir.

Yes , good question. Not having actually seen an actual Impossible 10x8 pack I just assumed it was like the it's Polaroid predecessor.
IE two components. A neg in a sleeve, loaded into a holder, then manually sandwiched with a sheet of paper before processing.
So is Impossible just one sheet with chemistry attached? Exposed then processed as per Polaroid? hence the reversed image?
Thanks Tim