They added the 2nd kick drum in the previous leg of the tour and I always wondered how much use did it really get. I think the answer might be none.
In this picture you can see the extra one has no mic but the standard one does.
I don't like the idea of adding instruments to the stage simply for looks. Seems a little cheesy to me.
That being said, I do like the flag on the drum. It's a nice signature for where he's been and since he goes to so many countries I like seeing it change frequently.