the material is loose, the suit comes with a neck opening which you slide over the bust head and can be adjusted and swiveled around without the fabric interferring with shoulders or arms, all the extra material and part of the shield was tucked under the bust.
That does absolutely zilch to address the points I made. In fact, your statement about the "neck opening which you slide over the bust head and can be adjusted and swiveled around without the fabric interfering with shoulders or arms" actually reinforces my point.
By your own words, the neck is the center point around which the whole thing can adjust and swivel.
Well, basic mechanics and geometry shows us that when you rotate something around a central point, it stays in the same place relative to the center point.
Here, let me give you a graphical representation. (see attachment)
The yellow circle represents the neck, or the center of rotation. The arrow indicates which direction the bust is facing.
The cyan represents the shirt and shield facing forward, in line with the facing direction.
The red represents how it would look if the material were turned about the center point as you suggest.
As you can see, the shield graphic has also turned along with the box, giving the top line of the shield an inclination from horizontal. However, Sebastian's own earlier proof that the shield's top line is parallel with the horizontal proves that the costume is not rotated around the neck, and leads me to my assertion that the shield is not centered properly.