I know this is probably a crap analogy but if you think of a train engine backing into a carriage and once they are coupled up the train drives off forwards both together - well that's what the swing is like, you create that box in the backswing then drive the entire box down towards the ball, you don't suddenly separate the box at the top once you've created it. It feels like you swing down until your shoulder literally can't hold onto the speed by which time your hands are practically over the ball and then the right arm straightens/extends thru the ball automatically.
If the right shoulder stays back then you have increased the distance between the bicep and the shaft (you no longer have a box), the right arm extends too early so now you either have to early extend your body to get out of the way of the club and/or flip it thru impact. It's easier to see from face on pics/vids.
If you look at your lower pic your right shoulder is not yet in place, (it's high) if you've stopped turning then you're about to flip the club. You're quite straight legged so it's as if you've made a little space to accommodate for the flip. It's not a bad position but it's just what's going to happen from there on in. If your right shoulder is still turning down to the ball then you're fine.... 
Lots of your swing is good... you just need an overall picture so you can sense what it is you should be doing. Your hands should be 7-10 inches in front of your nose at impact... that's the hard part.... left hip cleared, right shoulder down.
