Your back is straight, but that's not enough to create a good deadlift.
You forcefully push the bar forward when you set up (look at it rolling away), creating a big lever that you have to overcome. I do the same little motion to lower the hips before each rep, but next time just let the shins touch the bar - don't let them push it forward away from your mid-foot.
Then, on the way down, you try to sit the bar down and you have to make a loop to get around your knees, beacause you don't unlock your hips.
Correct these inefficiencies and post up an updated video.