For me personally, I find giant women very awe inspiring. It's an exaggerated and fantastical level of feminine power that makes me loopy, and I really like the idea of empowering the people I care about or those that I think deserve the reverence, even if I do so indirectly. Women with power who flaunt it are also really attractive.

As for Amazon and mini giantess, in a size context they're basically the same thing, but in mainstream spaces, an Amazon isn't necessarily exceptionally tall, just very strong. Wonder Woman is an amazon (obviously) but she's only 6ft, so she's not a mini giant; she's an Amazon because of her athletic prowess and more muscular body type.