What is the difference between a supplemental noun phrase and a absolute clause? In these examples and in general. Is it just the non-finite nature of the second example? Are they not serving a similar purpose?
He won at his favourite sport, the long-jump, and brought another medal home for the U.S, the most fitting conclusion to his brilliant career in track and field.
Noun phrase functioning as a supplement/ syntactically separate element.
He just stood there, his face clearly revealing his disappointment.
Absolute clause: called absolute because it serves no grammatical function in the sentence. It just adds supplemental information.