@mcc I guess it would depend on the overall design and art direction of the series.
@mcc
To be more precise, they are all AIs who have decided to get a body.
The precise specs of that body is up to taste and budget, so a nose is probably a thing they get because they would like to sniff things.
So basically if the body is anthropomorphic you can't know for sure until a nose is drawn or otherwise exposed because it's used for sniffing.
@onikaze