World famous sculptor Arnaldo Pomodoro creates these,
Arnaldo Pomodoro - Wikipedia
He is known for making sphere creations with many layers of complexity, These sculptures have taken off in popularity for many large organizations as they are symbolic of many working together as one or many working together as a whole.
Giant Fractured Sphere at the Vatican For whatever reason, this man is viewed as some sort of modern genius artist and his works are highly sought after worldwide, Here is a list of locations to all his public works,
Find all the Sphere within Sphere Sculptures around the Globe
I can't really comment on his skill, I've studied his work under high contrast in photoshop,
It seems his greatest skill is just polishing things to be really shiny. :/