Director A does not receive a Directors salary from the company.
So rather than director A receive an amount through the company payroll he receives it via dividend.
So once this amount has been deducted from the total dividend voted, the balance of the remaining dividend is then distributed proportionally to the shareholders.
in this situation the only way i can see it possible is if there are different classes of shares are issued to share holders (who are also directors).
unless i missing something?