I think it's just the mini version of their 4x4x4 but in white.
I don't think so. It is listed at HKNowStore here
as 62 mm (6.2 cm). The mini version was 6.0 cm. (The first one was 6.6 or 6.7 cm.)
It seems to be different from the original...
It is. HKNowStore has pictures comparing the original and this one.