Osmanthus fragrans blooms in September, that is, autumn, so "season of golden osmanthus fragrance" means autumn and "golden osmanthus fragrance" symbolizes autumn.
"Jingui fragrance" is not an idiom. Osmanthus fragrans has white flowers or yellow flowers and has a special fragrance, which can be used as ornamental and spice. "The scent of cinnamon" is a synonym for the idiom "the scent of cinnamon"
Description: Osmanthus fragrans blooms around the Mid-Autumn Festival, emitting a fragrance.