From Bulbapedia, the community-driven Pokémon encyclopedia.
The Veilstone Department Store (Japanese: トバリデパート Tobari Department Store) is a department store located in Veilstone City, west of the Pokémon Center. The store offers a wide variety of items on its five floors. A sign outside reads:
B1F: Food & Produce
The basement is a new addition in Platinum Version. Three of the stalls sell items. One sells Poffins for Contest use, one sells Berries, and the other sells Lava Cookies. The Poffins are level 32 and have a smoothness rating of 20. Another stall in the top-right is supposed to sell Rage Candy Bars, but they are sold out. Professor Rowan can occasionally be found here hoping to buy Rage Candy Bars.
1F: Trainers' Zone
The people at the reception counter sell items commonly found in Poké Marts.
2F: Battle Collection
On this floor, a man behind the counter will give away the Counter Pokétch app. Battle items and vitamins are sold here as well.
3F: TM Corner
TMs are sold here.
4F: Poké Dolls & Goods
Secret Base decorations are sold here.
5F: Rooftop Plaza
Inexpensive healing items can be bought on this floor.
When the player enters the Dept. Store, there is a lady to the left of the entrance who will give away a mask to be put in the Fashion Case. The mask will match the starter Pokémon of Professor Rowan's assistant (Dawn/Lucas).
3F-5F & Elevator