There looks like some damage to the decoration (paint?, glaze?) on the region at the upper-most part in that picture. If spun on that point it looks like it would topple and thus classify as a real top. Remembering the thread about loose ball inside a top for balancing, while spinning the small pebbles should not be rattling around inside to create noise except at the start and extinction. I wonder if there is damage that allowed the pebbles to be dumped out (thus they may not be original) or if x-rays for example were used to image the inside. If the pebbles are original and trapped, how is it decided to call it a top rather than a musical instrument like a maraca?