This achievement and all of the other Selfie achievements are very quick and easy...
From the main map screen press Y to enter the photo album.
Then select "City"
Select "Photo Booth"
You will then get a quick cut scene and be told to stand up (I did all mine sitting down)
Once the rabbids come on the screen a 3, 2, 1 countdown will start and a photo will automatically be taken.
A screen will show you your photo and ask if you want to save it.
Wait a few seconds and the achievement will pop.
Note: you don't need to save the photo for the achievement :)