1. Booker Dewitt's head and the top of the blue Salt bottle established themselves on the 'eye level' horizontal line, this creates harmony between these two secondary focal point and being on eye level means it doesn't exhaust the viewer's eyes.
2. Elizabeth's wrist is placed right in the center 'T' junction, this anchors her in a way it stabilizes her while being tilted at an oblique angle.
3. Elizabeth and Booker are composed in a triangle/pyramid foundation, what this does is that, the opposing force of the leaning of the body balance out the weight - if Booker were to lean at the same oblique angle, it will make it feels like Elizabeth is about to tip over and fall to right side of the frame lol
4. The rails at the two top red-highlighted corners enforce inwards to assist the flow of the Fibonacci spiral.
5. The splash of the Salt conformed to the flow of the spiral.
6. Her eyes has the highest content of sharpness being the focal point (do check out the real artwork as this one is pixelated and compressed)LIGHTS
1. The volumetric lights from searchlights behind her brightens up the background right behind her to creates 'contrast value'.
2. I used the same colour for the foreground as the background, that reddish smoke around her feet, to 'sandwich' the subject matter to create harmony of the whole imagery.
Hope this brief explanation clears up things and found helpful for references