Grammar in this clause "its weight a satisfying affirmation of my process"?
Here's the entire sentence: Over the weeks and months, that stack becomes heavy, its weight a satisfying affirmation of my progress.

I know that since the clause "that stack becomes heavy" is an independent clause, the last clause in the sentence must be a dependent clause. However, I don't understand how this dependent clause (its weight a satisfying affirmation of my progress) is grammatically correct.

Question

Grammar in this clause "its weight a satisfying affirmation of my process"?
Here's the entire sentence: Over the weeks and months, that stack becomes heavy, its weight a satisfying affirmation of my progress.

I know that since the clause "that stack becomes heavy" is an independent clause, the last clause in the sentence must be a dependent clause. However, I don't understand how this dependent clause (its weight a satisfying affirmation of my progress) is grammatically correct.

Answer

It is an adverbial clause with an implied "becoming" between "weight" and "a". This sounds natural in literary contexts but I would not recommend this style in other forms of writing.