I am not sure what you think those photos and video shows?
The video shows what you would expect to see from an arduino reading an analogue pin with nothing connected to it. This is the normal behavior from a fully working board.
The pictures just show a normal arduino.
mistake of connecting the pin that adjusts the contrast directly to gnd without resistance,
I can't see how this would affect the arduino, it might damage the LCD but you are putting a short on your USB power supply.
It is just possible that you have damaged the poly fuse however so get a meter and measure the 5V line and see what it reads.