Accidentally discovered this during my casual playthrough just now.

If you can smuggle a clone and a platform out of a puzzle and have the terrain to get onto the platform afterwards, entering photo mode as the platform-holder will leave your platform-standing clone parented to the camera, allowing you to place your clone anywhere within photo mode bounds.

You can use this to skip North 1 entirely, as demonstrated here:

That's a nifty alternative to qumping (jumping as you exit photomode to jump in the air forever).

This actually seems to work anywhere you can stand on a platform, although I'm not sure if something needs to be done to trigger it, and I've encountered some weird behaviour where the platform-rider stops moving with the camera, or seems to move in a direction really quickly when the photo mode closes.