[Izuku slows to a stop, looking at her in surprise. There's a lot to unpack here??]

You're a persona user? There's a few other like you here--maybe you guys even know each other!

[And while he'd normally begin to ask questions about her persona, there's something else here that he just can't help but get stuck on.]

Wait...you're a machine?? [Wide-eyed, he looks at her face, studying her more carefully now.] Wow...I couldn't tell at all. [That's some impressive technology, there.]