Think about it! She is supposed to be close to the original vastayashei'rei and yet looks so human. What if she keeps this appearance because she is around humans just so she can blend in better without trouble ¿
I doubt it. More likely Riot found zoe was a good target for marketing and are just running with it.
It's not really about whether she's similar to Zoe or not but simply that associating closely with humans makes her more endearing. A true shapeshifter would be formless. Even though Riot is insinuating that she's Vastayashar'ei they are putting inconsistencies in the bio (where it says that she is Vastaya) and voicelines (where she says that she's Vastayashai'rei)
