During the X-mas sale, most likely.

Originally posted by チルノプリズムゲーミ:

points shop seasonal badge

when is going to be a new one ?

We get 2 per year, Summer and Winter. It even says, "Check back during the Summer and Winter sales for an all new seasonal badge."

The Winter badge will be there when the Winter sale begins on December 19th.

And yes, the first day of Winter in the Northern Hemisphere is actually on December 21st this year.