For a look at the 3DS-specific character creation and gameplay in action, check out this review:
This feature allows you to automatically trade your created Sims with other 3DS players you pass by in real life. The Sims 3 3DS (EUR/JPN) CIA
If you are using a on a hacked 3DS (e.g., using the FBI installer ), be aware of potential region-related issues: For a look at the 3DS-specific character creation