MIRRORED REAR-VIEW MIRRORS
At Spa, the RB14 was equipped with blown mirrors obviously inspired by those of the Ferrari SF71H (and already copied by Toro Rosso in Great Britain).
This kind of rear view mirror has an opening on the front of its fairing. The air enters and bypasses a second fairing (internal and made of carbon), before emerging on the other side around the mirror itself. It seems that this hollow fairing of the mirror does not serve to direct the airflow towards the upper sidepod inlet, contrary to what was thought at first.
Simply, its role would rather be to improve the airflow towards the rear wing and diffuser. Its shape would certainly create a little more drag, but it would also generate a wake of higher pressure, more energized than with a conventional design, which helps the elements further down (the rear wing and the diffuser) in generating downforce.