In the second to last picture, I'm not looking at the first concho
, I'm looking at the rivet that's on the leather part of the saddle. I line that up with the first concho you get to as you move toward the back of the saddle. That rivet on the leather part of the saddle marks where the bar starts, which is what needs to be behind the horse's scapula at MAXIMUM extension. If that rivit is in front of that spot where the horse's scapula is at max extension then you will block her shoulder movement, which will result in her rounding her shoulders forward (a lot of times causing a rotated shoulder) which dumps all the weight on her forehand, thus making her strides short and choppy. Her back will be hollow and she might carry her head up high and bracy.