Hi,
Magpie belongs to crow family, but in the instance above you have a "Magpie" Robin.
'Magpie" relates I believe to "magpie type" in the same way that "Rufous-tailed Robin" refers to a Robin with a Rufous Tail etc,
I am not a botanist, but when classifying for HKBWS purposes would think it falls in "thrush" category.
Having said all that, I am quite happy to be wrong, but just thought it should be a Thrush.
All the best......... Guy