How to so this effect on a camera?

I saw my cousin taking this picture of birdhouse, and around the edges there was a swirl effect, and the birdhouse was in focus, and when she took it she would move her hands and camera in some way. I don't know if that makes sense, but basically she did this without editing the picture. She had some big nikon camera.thanks! How do you take a picture witht his effect?

Added (1). I have a nikon rebel XTI

You don't even know what camera you have… The Rebel XTi is a Canon camera.

Hmm, there's a Canon Rebel XTi, maybe that is your camera? You may be describing depth of field. What that does is blur the background, and sometimes the foreground of a picture. It is done by having a wide aperture (low number) on the lens, zooming in (if you can), and being close to the subject.

The Rebel is a Canon entry-level dSLR model lineup, not Nikon.

There's no way you can move the camera and let that birdhouse stay in focus. If what you meant was that the background was blurred and the birdhouse wasn't then it's a simple matter of depth of field (DOF). Basically, the larger the aperture size (smaller f/number) used, the shallower the DOF, the lesser objects stay relatively in focus.

To make it easy, put your subject as far away to the background as possible and position the camera to the subject as close as possible. Set the camera to aperture priority, select the smallest f/number then shoot.