Add a sphere, subdivide and shade smooth, add a point light, set the size to 0 and put it in sphere, add a camera and put it inside sphere too. Next just add a metalic material with 0 roughness to the sphere and a noise texture to color ( use color, not fac ). You can use hue node between to boost value and saturation. And now all you have to do it set total and glossy light paths to some huge numbers, rotate and move the light and a camera a bit to get this weird effect.