That mall at Principe Pio does not have the best shopping, (sorry).
If you want shopping, go to the center by Sol, Shoes-go to C/Agosto Figueroa in Huertas district north of Gran Via, and if you really want a mall-go to Xanadu, it's on the outskirts, you can take buses there. They have everything, even a ski mountain.
The shopping is the same as in the center of town but in the summer heat, it is enclosed and air conditioned.
You did ask for outlets-so the Factory stores are the place to go outside Madrid.