My sister-in-law has been begging me to make this photoshop construction for a long time. Finally on Saturday I took the pictures, and today I spent a disturbingly small amount of time (< 5 minutes) photoshopping two photos together.
One interesting thing that I discovered in this endeavor was that it's really hard to move a 7 kg weight from one side of your body to the other without drastically changing your posture. On the photos with Nora on her right, her hips were exaggeratedly to her left, and vice versa. Her all-black outfit helped a lot, making the photoshopping much easier. I merely aligned the two layers and then let one layer shine through using a layer mask. I think the result is pretty impressive considering the ease with which it was made.