She does have a ponytail, actually. It's all braided up tight in a way that would require her to either have a lot less hair or be borrowing Atom's dwarf star tech, plus the shagginess of the front makes it kind of a mullet thing, which is even more horrible, of course.
The epaulettes are why I'm not certain the Jimenez drawing is actually her. It's a much more sensible pair of pauldrons, but the absurdity of the shoulders is probably her most distinguishing visual feature.
Diana's costume, though, barring the slightly funky boots, is a huge, huge improvement on standard. It makes me weep how little you'd have to change it to make it a hundred times more tolerable - I mean, is there anyone who wouldn't recognize that costume as Wonder Woman? It's hardly a radial difference. And yet, it has so much more dignity and plausibility and aesthetic consistency.