The pull isn't bad but your shoulders are a little in front of the bar, crank them back and stick your arse out more. On the negative however you appear to have some lumbar flexion most likely from not being able to hip hinge properly. You need to be able to quickly and dynamically shoot your arse back, hinging at the hip with no loss of stability in the core. It's something to work on away from working sets because it will just take time. Try doing some RDLs with dumbbells, pushing your bum back as far as possible, then when they get easy swap to doing single leg RDLs in the same way.
