From Bulbapedia, the community-driven Pokémon encyclopedia.
Walda Pepper (Japanese: アヤノ Ayano) is a young girl in Rustboro City who is very sick, and could really use some cheering up. Her father bought her multiple Poké Dolls, such as Pikachu and the Hoenn starters, to cheer her up, but it hasn't worked. If the player is able to say something to make her laugh, her father will reward them with a new wallpaper for their Pokémon Storage System.
Words that will make Walda laugh usually consist of random characters and depend on Trainer's ID number. Generators like on filb.de can be used to create custom wallpapers.
|| From 文 aya, design.
||From bercer, to rock.
||From Tapete, wallpaper.
||From papel, paper.