I'm just guessing, of course, but it looks to me like one of these things might be meant to be worn under the other.
I grabbed the back view of the sweater because from the front it looks lovely, but between the back zip and the implicit admission of an itch&heat factor, making some kind of tank necessary, I will need to be reminded not to buy these pieces. No matter how enticing their final names and descriptions are.
Meanwhile, taking due notice of this past week's trend of extending sales, promotions and barrages of catalogs (all but one), I am extending our little stocking stuffer give-away for another week. Details for entering and for the goodies are in this post. If these seem too complicated, just post a little comment saying you'd like to enter.