Cabin light comments:
The videos suggest either one engine or the APU is running as IFE is powered (AC only).
Emergency lights on the 777 are self powered and come on automatically if the main DC busses lose power. They can be manually activated by CC or from the flight deck. Since the aircraft appears to have AC power, the DC busses are also powered, so the automatic function would not activate. While the cabin emergency lights are not all that bright, the parts of the videos that show the dividers and seats along the aisle suggest definitively they are not on.