Well, I haven't seen any piano with this key size that for Yamaya is "full size".
Keys size may vary, ok, but the reality is:
no piano nor professional keyboard has this key size, which is named standard for Yamaha, but is smaller than standard for the rest.
Why Yamaha? Why PSR's keys are smaller than any piano or any non-Yamaha keyboard? There is no logical reason. Only is a Yamaha tradition.
So, yamaha would say it: "Yamaha size keys, smaller than the rest"
It is only my h. opinion, of course