Maybe the linking of both Earth and Quintessa? Or idk maybe that's how they control mass amounts of Cybertronian metal or technology
This ^ Looks like a bunch of portals to different locations/worlds/universes. Wouldn't be surprised if this is the result of the human group, KSI, messing with space bridge technology. For the events of sequels to potential take place I wouldn't be surprised if Galvatron is defeated in this room in a 'portal explosion' or something similar so he can appear in the next film having just been Transported. Alternatively, he could get transported to Unicron for a end-credits scene...
could just be the power source for the ship. who knows. but i too found it interesting in the trailer.