For me, this party is important because Emmy meets Gage and the true identity of Gage. As far as I remember, Gage is somewhat wanted in the capital because of Emmy or broke a law (I think)😅😅.
I think Gage was once somebody important but then did something that was frowned upon by high society... or just society in general. Like maybe others thought he was a bad guy, but maybe he was just misunderstood?