Beautiful barrel!!!
That's a 5-year old, BIG! barrel, so it is not going to impart oak very fast. If it has been filled for that long, there won't be much oakiness left to impart.
If it doesn't seem to be adding any oak flavor, you can put a bag of oak chips/cubes in the barrel to add more oak flavor. Chips and cubes will add oak for about 6 weeks before they should be discarded. Tie a small string to the bag, so you can easily pull it out of the barrel.
You don't really need to top off that barrel on a weekly basis. That is pretty often to be opening it for such a big barrel.