This is the 396th most frequent Italian word.
unico
Unique; only; one of a kind.
The word 'unico' here emphasizes the extraordinary quality of the gift, making it different from others.
Questo regalo è unico nel suo genere.
This gift is unique in its kind.
In this context, 'unico' describes a distinctive quality of her painting style.
Il suo stile di pittura è davvero unico.
Her painting style is truly unique.
Here, 'unico' is used to indicate that he is the sole person among a group who has completed the exam.