hi, so maybe my initial words of choice in my post wasn’t the best. while the poster does have his shoulder retracted, he is not pushing it down. so let me try to to rephrase it again in a different way, push your rib cage back behind you to the ceiling while at the same time your scapulas are pushing diagonally down almost like as if you’re trying to activate your serratus anterior and with proper core bracing and glutes tightened it just looks like the upper back is rounded and when you try to bend the bar the lats will be completely flared out and activated. although genetically we all have slight variations, but the functions will all be very similar in movement patterns.