Originally Posted by
ZaneBusby
It's all about the base mastery levels (which I've taken the liberty to underline in that pic. The green digit is the amount of mastery from gear/buffs). It has no effect on the scaling/value of mastery whatsoever, it just buffs the base amount of mastery at level cap, increasing damage. The only side effect of this is a minor buff to lesser geared players in the process, but lesser gear is irrelevant anyway (level cap is NOT balanced around heroic 5man gear at this point), and it would only be very minor, probably almost negligible...
Not that it matters all that much, because he's already shoved it off to the side, just that I find it amusing.