Why does the suspension look like i drove over a rock?

Ok so i have play my latest video over, and over, and what i noties is a.... vibration of the spring pack on the left one. Just behind the axle. This could just be the blur of the video but it happens at the hop...............
I my have tighten them shackles to much and it's causing a bind just like 762bluNblu suggested.

What are you guys seeing?