Once you have beaten both the R-1 mode (including Mewtwo) and the R-2 
Mode (including Mewtwo), you are given a set of bonus stickers that you 
can access in the Gallery Mode. When you're on the Gallery main screen, 
press and hold L and R and move the Cursor to Print. If you keep the 
buttons pressed, the Print option will now change to Bonus. You will 
now have access to a set of 16 bonus "wallpaper" stickers from all the 
different modes that you can print out at "Snap" Stations.