Some people have already theorized this shout out to them, so I'm gonna through my hat in the ring.
I gonna predict that this scene
Takes place after Andrias sends this robot after Anne. Of course Anne beats the robot so Andrias is like "hmm how am I gonna get her gem power? Oh I know I'll send her friend to do it for me"
So he let's Yunnan and Olivia rescue Marcy.
Now Marcy is still herself not a spy or brainwashed, However this tech chest plate is possibly where the Night resides. And it's able to take control of Marcy whenever it wants to.
It'll make for some interesting conflict because Anne might need to choose between freeing Marcy and the world being taken over. If that chest plate is the only thing keeping her alive.
Either way I am pumped for Season 3!!!