About the thing David is pulling;
Watching it, it looks like four seperate glass containers, with ooze clinging to the bottoms as he pulls, but also the clip he uses is holding onto four seperate finger or maw-like protrusions, each with a strange black talon/fang/claw thing on the top. I can also clearly see a spine/facehugger tail. However that could be some kind of central tube to the fixture of the inside of what I'm guessing is an ampule (note it looks like white plastic, non-tapered, rather than the tapered chrome ampules we've seen).
I dont know what David is pulling at, but the finger-maw like things restrained by the clip (I expect the clip was also in whatever was opened, most likely some type of ampule to be fair - the clip must belong to the interior) make me wonder if we are looking at a type of "proto-hugger".