How do the pronoun and circumstantial wāw differ in function?

Wāw with Nominal Circumstantial Clauses: Omission, Inclusion and Disputed Cases

• Both are individually obligatory in every nominal ḥāl
• Pronoun identifies the bearer; wāw makes circumstantial relation explicit
• Wāw identifies referent; pronoun only marks temporal relation
• Wāw and pronoun are fully interchangeable