Kyle Jones, a guitarist, had the clever idea of recording himself playing guitar from inside his guitar. He didn't expect to see the guitar strings turn into wacky, wavy and shapely lines. It's crazy. And it's thanks to the iPhone.
Like when the iPhone's camera captured floating blades of an aeroplane propeller, these crazy shapes that the guitar string seemingly takes on is caused by the rolling shutter effect of the iPhone's camera (when digital camera's take a picture they actually scan over a frame either vertically or horizontally. Basically, not all parts of an image are recorded at exactly same time and some parts are left playing catch up.)