I think better question is this: How does Iris expect to become a Dragon Master if she barely trains her Axew? Of course her ice phobia is also a bad thing, though.An okay filler episode, I got a laugh at Georgia calling Iris a kid. Her having Ice types was a smart idea only because Iris is afraid of them. Though how does Iris expect to become a Dragon master if shes scared of them? Its a little ridic and she might as well quit. Did working with Vanilluxe diminish her ice phobia though? It was left rather ambiguous in the end.
About Iris diminishing ice phobia in this episode, I don't think so. I think she's now somewhat less scared of Ice types and can work with them if she has to, but I doubt her is ice phobia is entirely gone.