here is my view of this picture ( got left out in previous post )...others might hold a different opinion.
a simple looking picture but with much thought goes into it.
* daring composition, bending the rule of third, by placing the main subject in the bottom
right corner. In contrasting, other might let the bottle cap occupying the whole picture
* using sharp and blur focusing to differentiate them.
* using contrasting vivid colour to draw attention of viewer.
* simple lighting technique.
* the space left over could be use for text filling, if used commercially.