The Christmas tree is a décor token.
You may place it in a room consisting of two or three cards (not including the garage). You can have only one Christmas tree in your home. The standard décor rules apply otherwise.
To get a Christmas tree, after you take the pair of cards from the column of your choice, discard the resource card and replace it with the available Christmas tree token with the most points.
For more information, visit the BGG listing.