If male viera are ever added, the devs will probably make the male viera face similar to that of miqo'te, while their bodies will sort of be like elezen - just with better proportions. Female viera is the same way. It would be nice if the males were shorter in my opinion, but I think the males and females will most likely be around similar heights.
Female rabbits and hares tend to be larger than their male counterparts.
"Rabbits and hares are unusual among mammals because females tend to be larger than males."
http://www.biokids.umich.edu/critters/Leporidae/
Maybe there is the odd species of rabbit where the male might be the same size as the female or a little bigger, but that is not the norm. There is a clear trend in females being larger than the males. Females are bigger in size and they also weigh more.
As a side note, male rabbits tend to be more easy-going and relaxed than female rabbits.
"Male and female rabbits are distinctly different from each other, even after de-sexing. Males tend to be more easy going and relaxed while females are usually "the boss" of any household. In the wild, rabbits pair up into couples with the female digging their burrow and the male defending her and the burrow against intruders."
http://www.bunnyhugga.com/a-to-z/rab...rsonality.html
I thought this was kind of interesting because it's similar to how viera are portrayed. Female viera seem to be the "boss" of their homeland, while the males are sort of out there defending the females that are tending to their home.
Aside from the obvious rabbit ears, it's possible viera were inspired by rabbits in other ways. I already mentioned how female rabbits tend to their burrows, while the males are defending the female and the burrow against intruders. This is similar to how viera live in the game as well. Of course, this could only just be a coincidence, and the behavior rabbits display in the wild was not used as inspiration for the viera lifestyle.