Take a look at the piece of wood above and ask yourself how that nail got there. It's no photo trickery, the nail is actually where it looks to be. So how did they do it? Those of you who've worked extensively with wood, understand its properties inside and out and are familiar with operations you can perform on wood to temporarily alter it will probably figure it out. For the rest of us it will be a surprise.
(You may want to turn the sound down on your computer, the video has a pretty annoying soundtrack.)
While not a practical technique from a time perspective, I'm guessing this trick does have applications for some visually interesting furniture joining techniques.