2. Touch a wallpaper source:
Gallery. Choose from pictures that you've synced with your
Live Wallpapers. Choose from a scrolling list of animated
Wallpapers. Choose from thumbnails of default images, or
touch a thumbnail for a larger version.
You can download additional wallpapers on Google Play.
3. To set a wallpaper, touch Set wallpaper or, for Gallery images,
determine the cropping and touch Crop.
To change your tablet's wallpaper, go to Settings >
Device > Display > Wallpaper.
Nexus 7 Guidebook
MAke YouRseLF AT HoMe