My personal speculation on Roxy's theme and playstyle
Obviously, it's still too early and I'm not saying I'll be correct, this is just my personal tin foil hat moment of what the character's theme is going to be for fun.
Lots of people says that she has a zombie motif like Corin, but in my point of view what if it's not zombie, but a necromancer?
Think about it, she has skeleton motif all over her, the tombstone symbol that says rip and fences like it's a graveyard. She's also seem to work in the same faction with Claret who has vampire motif like a bat mask and in most fantasy, vampires and necromancers tend to work together.
Okay, if that's the case how will Hoyo fullfill the necromancer fantasy ingame while making sense in zzz's world? The final nail in the coffin (pun intended) for me is that based on the trailer, Roxy works in a faction called Flint Workshop. With this I deduce that Roxy has a knack of inventing stuff, possibly if necromancy is her theme, mechanical puppets?
With this, I think it would be cool if she's a support or stunner character that sends mechanical puppets/minions to help dps damage/daze.
Again this is just my personal speculation on Roxy, all of this could just be me overthinking on a character we barely know anything and be completely wrong. But part of me hope I'm correct since I love necromancers in video games and this will be Hoyo's take on it.