So the Vex part is extremly interesting to me.
If i remember correctly, in the reveal stream for the Floating Gardens, it was described as a place where Vex units discard their frames that have been damaged beyond repair. The core of the Vex are the radiolarian fluid, or the vex milk. Now Radiolaria is described on wikipedia as zooplankton in the ocean, which could be important.
So in the video, we see a Vex Unit, seemingly unpowered, floating in liquid (lets calll it water) Then a stream of what looks like vex Milk worms its way into the center core, and the Vex frame powers up.
Putting these things together, i speculate that what we are seeing is the birth of a Vex unit, or rather, the Vex min fluid entering a frame and with that, powers that frame to become one with it. I could go so far as to point out the “aim for the juicebox” part. If we look at a way of viewing that, a juicebox could be the thing that gives Vex power, which is hinted at in that video. The Milkie substance powers the unit on, or turns it on at least.
This is all happening under water and i think that is important. Radiolaria is seemingly waterbased, so perhaps the Vex milk (if thats whats being shown) cant exist above water or liquids. This could explain both why the black garden almost feels like its underwater, and why when we shoot the juicebox of a Vex, it dies, because we expose the radiolaria fluids.
Deej once described the Vex as a liquified race, so i would theorize that that milky substance i call Vex milk, is moving with a purpose and not just shot there, its a living organism, which also fits well with a liquified race using frames to actually impact their world.
thats my thoughts on it, i would love some comments on it