It seems that Wargaming intends to test customization elements and loot boxes using this event.
The whole thing seems quite complicated at first – it seems to be a system of decorating a Christmas tree with toys from loot boxes.
It is supposed to start on the 16th December on the RU server, nothing known regarding the others.
Boxes can be earned for combat missions. A box contains 1 to 3 random toys for the “Tanksman” (snowman) and the Christmas tree and an additional reward.
Boxes come in different tiers – blue, green, orange, purple and yellow and can contain boosts (personal reserves), medpacks, repair kits, 1 day of premium, garage slots, discounts.
The event also comes with a story part and easter eggs. Medals will be given out, which were published yesterday.
The RU server also has a dedicated advertisement page for it already: http://tanki.su/
Customization elements / toys:
Christmas tree: