According to the McDonald's China website, the item and returning pudding-flavored soft serve comes in celebration of the first anniversary of the "Golden Arch," which seems to be a reference to a change of the company's official business name (but not the name of the restaurant) to "Golden Arches" in China last year.
In addition to the special jumbo cone, pudding-flavored soft serve ice cream can also be enjoyed in a cone or as part of a sundae or McFlurry for a limited time.
Photo via McDonald's China.