I came across this milk carton from the trash, and it caught my attention due to its unique twisted form that creates a very sophisticated angular lines at the side of the object.
Dominant (D) of this object will definitely be the twisted carton itself as it gives the most visual weight.
The blue cap really stands out due to its contrasting colour, and also how it is the only part of the object that has an circular axis to a cylinder. This milk carton was made mostly with paperboard coated with waterproof plastic, only the blue cap of made entirely from plastic which makes it even more contrasting than the rest of the parts that form the milk carton. Hence, I would describe the blue cap as the Sub-Dominant (SD). I wouldn’t describe it as a Subordinate (SO) as it gives substantial amount of visual weight but less than of the Dominant.
I think this object is proportional as the SD is placed at 1/3 the height of the D which give a good visual balance.