Her character is reminiscent of a number of Star Wars aliens. And this is all supposition and maybe this role is pretty important and she will embody it well. Nothing to do with seeing her as another Megan Fox (although nobody put it that succinctly). If a male were cast for this part, Cumberbatch say, I'd have the same sort of question (though leaning more in the direction of it worrying it's a big star cameo). I just see Lupita's combination of looks and talent a highly potent combination and I can't help question if this is the best use of her potential. I suspect she will do a great job and prove her acting ability, don't get me wrong on that!