More attention on you
A second shooter is a secondary wedding photographer who will accompany me to your wedding day. Their primary job is to capture the general atmospheric hustle and bustle of your wedding day, and candid photographs of your guests so I can focus my attentions to you, the wedding couple.
Also, having both our attention on you at the same time is an added bonus. Walking down the aisle for example, I sadly can’t split myself in two (one day, maybe), but allowing us to have one of us at the back of the ceremony and one at the front gives you a whole other outlook on your wedding entrance and enables us to capture both your emotions and first glances.
This also links into my next point;