How to make this out?

The way is actually quite simple. Eirik found a spot on his balcony where he could place the camera in the exact same spot each time. Then he recorded video clips at irregular intervals. More or less once a week all thorugh 2009. More often during spring and autumn and not that often during summer and winter. All the videos are then put together using lots of dissolves. Here's a video link to explain the process.

The video was created by Eirik Solheim (@eirikso) | Camera: Canon 5D Mark II