She's just been booked as a monster and she needs to feel like a monster to beat Becky (considering Becky has got the Cena/Roman treatment as far as booking goes).
It's also not a dissimilar style to the Brock vs Drew booking with the Royal Rumble match, except in that case the face will go over Brock. Make your heel look like a monster to elevate the challenge for your big face. As it stands, Shayna is that weird goth chick who bit Becky for those who don't follow NXT. This makes her feel more like a legitimate top carder who could actually defeat Becky.