This FIRST image is a 9-shot IN CAMERA multiple exposure.
The SECOND image is a single exposure of the colorful scene you see here AND finally, a 16 second video, showing you how its done. IF you have a Canon 6-D, or 7-D mark II, 5-D Mark ||| or higher, or a Nikon D800/810/850, D300, D500, D4/D5, go to Multiple Exposure Menu, Choose 9 shots, Choose Average for Canon, Auto-Gain or Average for Nikon, then choose Continuously for Canon or Series for Nikon...with your street zoom i.e. 24-70, 24-105, 24-120mm set zoom to wide-angle, then grip the zoom ring of the lens somewhat tight, and as you now shoot the 9 frames, turn the camera body in a fluid motion, NOT THE LENS, and voila, the effect is like water going down a drain.
Now, watch the video to see how to hold the lens and turn the camera.