Your WordPress theme's article has a wide layout, i.e it spans the entire width of the browser window.
So you either make the 360 product viewer fill in the entire article width by setting width=100% inside the shortcode, which will center your 360 product images and the viewer toolbar, or you would also need to wrap the shortcode into an extra <div> and center that div inside the article which will center the viewer as well.
Your theme's css seems to have a wrapper class that can help, so try to enter <div class="wrap"> just before the shortcode and then </div> right after the shortcode (keep shortcode width=100% as well so it fills the entire wrap). Hope it helps!