All the female characters have become really short.
Not really. Annie and Christa ARE that short, as are Rico and Petra, Zoe and Ymir are simply bent over (and Zoe isn't that tall to begin with), while Sasha and Mikasa are of their realistic height: Mikasa is 170 cm just like Eren (and Zoe, BTW), but she's a couple paces back, so she just looks shorter. The bigger problem is that half of the characters were dead even before the other half was introduced, so they couldn't all be together in that picture. ;)