The clumping seems excessive but who knows it could be something that they selected for in propagation, what the main question is to me is does it have black tipped spines, from the picture I'd say not, and afaik most geminispina have black tipped spines.
I have one that is clumping a lot, but not quite like that, but it means that to me the clumping cannot be the main reason to say it is not, but combined with other reasons it could be an argument.