Ok, maybe the picture is there because it is an official product image from TLG.
So they are also using the wrong image in their own online shop.
According to TLG's description of the set, it contains only a 32 x 32 baseplate...
This picture is shown on all platforms, including Bickset and Brick Owl, and
also as you say in the LEGO online shop. The description however clearly identifies
the baseplate as 32 x 32 sized, and the price (identical to bright green and
blue 32 x 32 baseplates) matches with this interpretation as well.
It would have been quite surprising if a 48 x 48 baseplate would have come out
in a new color. Baseplates have become much more rare than they used to be.
Ok, maybe the picture is there because it is an official product image from TLG.
So they are also using the wrong image in their own online shop.
According to TLG's description of the set, it contains only a 32 x 32 baseplate...
Great that it is now confirmed that this will indeed be a 32 x 32 baseplate.
So long ago that a white baseplate was available. Fits perfectly to this time
of the year, and the 32 x 32 size makes for a smooth integration into any city
layout (particularly great for mounting all the arctic stuff on proper baseplates).
Germany, Nordrhein-Westfalen
Spain, Comunidad Valenciana
USA, California
United Kingdom, England