If you look at 0:13, your wrists are straight over the bar. I can't have that. If my wrists are to be over the bar, then they have to be bent at perpendicular to the bar (bent to the maximum amount if you will). Otherwise, if I were to keep them straight like you do at 0:13, they'd be much lower than the bar. I have no idea what that means in terms of flexibility... maybe... what... shoulder inflexibility? I kind of feel the strain in the scapulae as well if I am to force things up.
I tried things with a wider grip and it was actually worse because my wrists came at an angle vs. the bar instead of straight "up". There's also the BAD (very, very bad) issue of the bar slipping on my t-shirt on my back and loading the arms. It doesn't sink into anything, it just slips down my back so I have to struggle to keep it there. I tried raising my elbows, contracting my back, doing all kinds of things to prevent that but the truth is that I really have to work fast and finish my set before the bar slips so much that it destroys my arms completely.
PS. You have the meat to let the bar sink into something