I think the idea is to look and be comfortable. That's what the bones hanging from the ceiling all in their rightfull place and not with the shoulders lifted to an unnatural position. That's what its all about .
If you were being taught a few years ago the left elbow was to the rear of the ribcage. The right elbow was to the front of the ribcage. Now both elbows are to the front. The other way felt like I was opening the left side up. Which it was.
Breathing. It is possible to breath in inhaling into the stomach, and out goes the chest. Or you can breath across the body. I believe singers are trained that way.
Fortunately I've never had any trouble with breathing. Singing and I am in trouble.