I think the most important thing is that it should lerp the closest side towards the camera, and it should do so with respect to the bunny's 'up'. I uploaded a quick demonstration of what I mean, check my profile.
Secondly, I think you should always know where the bunny is. Some ways would be showing the bunny to the side of the cube, either with an emitted light ray or an image with a pointing arrow or something, or showing the bunny transparently through the cube. Maybe a sound effect in left/right ear helps as well