This Gas Giant planet is a binary with a much more distant ice giant (not pictured). Over the course of 6 billion years, tidal forces have pushed the two planets away from each other, trading the gas giant's rotational energy for the ice giant's orbital energy. The gas giant now rotates only once every 3 months.
The ordered cloud bands of a typical gas giant are, like the Hadley cells in Earth atmosphere, the result of convection cells pulled into belts and zones by coriolis forces. On this slowly rotating world however, with effectively no coriolis forces, the convection cells have taken on a disordered, random, scale-like pattern instead.
Some tidally locked gas giant planets also rotate slowly enough to break up the pattern of cloud banding, but as those objects are generally close to their stars, their weather patterns are dominated by stellar energy heating up the day side. This planet, by contrast, orbits far from its primary star, and so its weather patterns are like Jupiter's: dominated by upwellings of internal heat left over from the planet's formation.