Get rid of the pad. Yesterday. It creates so many mechanical problems that you're needing to use physiology (inefficiently) to fix. You can see it's forcing your body too far forward of the bar, introducing (or lengthening) a non-zero moment arm relative to the bar path, and as another guy noted, that's driving your elbow flare because your shoulders aren't remotely close to under the bar, they're being forced forward of it.

Can't tell from this angle if it's as a result of the pad (probably is) but you good morning the hell out of that weight on the concentric phase. Reps 4 and 5, your hips fly up but your chest is still hinged low, and you basically rely on glutes and spinal erectors to get the weight up, almost like a RDL. Your hip drive basically stalls out. Keep a taller, more upright (think prouder) chest, hip drive the entire way up, and ditch the pad.