Beaglebone Black LCD shakes if image changes

I connect a 5.7’’ TFT-LCD with Beaglebone Black, through the GPIO pins from P8 and P9, If the image never changes, the LCD never shakes, otherwise, LCD shakes with image changes, please help! Thank you!

Here’s the video I uploaded to youtube:

http://youtu.be/XTPLcMzWtOA