It’s a very rare phenomenon where the observer sees a primary and secondary rainbow occurring together with their reflected-light counterparts.
The second double rainbow (seen here in the left) results from the sun’s light reflecting off of a nearby body of water. The smooth water surface reflects the sun, such that a second solar light source is generated. This reflected sun creates a second primary and secondary rainbow on the opposite side of the sky from the sun. This rainbow was spotted on the isle of Terschelling, Netherlands.
(Image via: Christina Burdette) – (Explanation: Jason Samenow/Meteorologist)