Twintails has to take several moments to process what she's seeing.
Her initial gut reaction is mostly alarm and confusion. It's not like she's never seen an image of herself — water is reflective, that shiny stuff humans use is also reflective, somehow that not-eel's face was reflective — but the image has never been this clear, and it's never been anything other than a reflection, which this clearly isn't.
Beyond that, the fact that it moves startles her pretty badly.
But once she gets past that adrenaline spike, she doesn't take long to understand that this is… sort of like the… phone…? …was looking at her, and now she's looking at its memory of looking at her? …Wait, is the ?phone? alive? Can it think?
Pondering this makes her thinks of something else that gives her another adrenaline spike.
She points at the video. "Is that a copy of me?"
They claim they don't have magic, but they keep implying that their not-magic is really really powerful, so she doesn't know for sure that they can't copy people.