Rubbish - intentionally misleading people!
The BASIC PAY is reduced by 9,000HKD for Captains and 8,000HKD for FO's.
Regarding 'flight pay' - you are 'at work' for fewer days (20/10) but HKA policy is that everybody does at least the basic 50hrs per month, so you will do 50 hrs minimum, and that may mean you may have to work your ass off during the 20 days you are at work.
Double whammy - a pay DEDUCTION for the SAME productivity.
If you get to 78hrs in that 20 days (as the JetJockey suggests is possible) you'll be dead on your feet. Remember HKA is still mainly a shorthaul airline.
Oh, and don't forget, they take ALL of your Annual Leave away too.
Enjoy!