Stance looks a bit wide. Not so wide that it couldn't possibly be the right stance for you, but it's something I'd look at.
Your ultimate back angle looks OK, but get there sooner - don't still be leaning further over at the bottom, already BE as leaned over as you need to be by the time you're halfway down. You do this better as the set goes on.
Stay in your hips on the way up, don't try raising your chest when it gets hard. Stay leaned over and drive hips.
Finally, your elbows may be too high. You only need them high enough to hold the bar solidly on the shelf back there, it looks like you may be cranking them up unnecessarily high. Give this a read for more info: The Elbow Problem | Jordan Feigenbaum