It seems to me from the video you got a stagelights effect too on the bottom. That might be usually caused by the screen itself, screen connector, or by resistors along the backlight circuitry. You can try reseating the connector (turn off and disconnect battery connector first) and clean the cable end with a couple drops >90% alcohol. Other than that there’s not much one can do apart from testing the logic board and/or trying out a different panel. Anything unusual happened to the Mac in the near past, bump or excessive humidity exposure ?