Review on ELECROW 8" Portable Touchscreen for Raspberry Pi, 1280X800P Display, Integrated Speakers & HDMI Support by Michael Darkshnar

It's advertised as a touchscreen for the Pi, leading you to believe it has everything you need to use it as a touchscreen with your Pi. However, when you plug it into your Pi's USB port, it flickers on and off, likely due to insufficient power. I suppose if you use an external power cord that goes into the DC socket then it will work. But they don't include it. They don't tell you to connect an external power supply to get the touchscreen functionality. Next. It works like a screen. If your screen keeps turning off, your cable or power supply is probably weak. Switch to a better power source and it should work I think.