The easiest way to explain this is time.
The time that we spend with the bride is significantly longer than the time spent with bridesmaids/others. It goes beyond the time spent on the wedding day, from start to finish we spend an average of 3-6 hours working with each bride. This starts from initial contact to trial, communications, and all the way to follow ups after the wedding.
We typically only spend 30 minutes with each member of the bridal party on the day of the wedding. This is a very standard practice in the beauty industry when it comes to weddings.