I don't know if there's an art of masturbation, but if it exists (and I think it does, after all not everyone can make it beautiful) I think Belle mastered it a while ago.
Objectively: there's nothing really special about this video
Subjectively: if you find the preview exciting just buy it, because Belle is and I feel weird saying this: the most fascinating fapper of all.
If you're after genuine pleasure not something acted to make you hot, this is the thing. Belle is a treasure.