Comparing the lionhead rabbits + old artworks from the FATE in tokyo, I can only assume male Viera ears do not look like normal rabbit-ears but of those lionheads.
I start to believe male Viera are dimorphic. The mane could be either face hair (beards) or actually chest hair (artwork). The end result might look like lions (as the leaker assumed the "icons" of this race). Also lets not forget, all Viera appear to have the same build til the age of 13. This also means their ears (the spot they sprout) are probably on the center of the head as well. (Compared to female Viera)
Im sure if someone would actually draw a sketch of a Viera with a mane, ears like a lionhead and made the face shape of a female Viera (small, round and with a button nose) + adding masculine tones, would end up as a "lion-lookalike" race.
Ronsos make 0 sense as we got none mention in FFXIV in the lore nor any mention of them appearing from overseas. We had the Return to Ivalice raid to tease Viera and this happened (just as they teased Au Ra with Yugiri in ARR).
If I dont remember wrong, Yoshida said he doesnt like male Viera because they looked to "cute". And we also learned from last FanFest during the Art Panel, that everything goes right into Yoshida's supervision. And since he does not like throwing away all the other ideas of the team, he told them to make a mix of said features. And thats why I believe male Viera look more like lions, than bunny bois.