To me, the last photo Bishop exhibits (see above) is the most intriguing. It certainly looks "real" enough to have cropped up in a TV or movie production but, curiously, its provenance remains unestablished. Note the twisted (?) neck, suggesting a fatal crash.
(At least one reasonably high-profile "abductee" with whom I've corresponded has expressed surprise at the being's resemblance to the aliens prevalent in his own close encounters.)