The subject may be repeated to honor or disparage a person, to seek blessing through a revered name, or because naming is pleasing. Such mention does more than convey reference: it helps establish attitude and tone.
هِيَ عَصَايَ
It is my staff. (Ṭā Hā 20:18)
Moses’ response begins with an explicit pronoun and continues with details about the staff. When an audience is attentive and further speech serves a purpose, expanding an utterance can be more suitable than the shortest possible answer. Extra words are not automatically redundancy.