Katie was rather tense as she saw her friend fiddling with the controls. On the one hand, she was excited to be transformed, as she believed stuff like that could only happen in fiction, and thought of the possibilities they had after they were done experimenting. On the other hand, she didn't know how Tiff was going to transform her, and was scared that the machine could malfunction. Meanwhile, Tiff was wondering how she would transform her friend.
"What to choose, what to choose? Hm, "animal" is nice, but I don't know how to take care of any pet... "Breast expansion"? I bet she'd like that one, I'll save it for later. Ew, "Transgender"... Then again, maybe Katie'd make a cute boy. Better remember that for later, too. Oooh, "Age regression"! That's perfect, I can make her even cuter than she already is! Let's go with that! Oh yeah, that's right, I still need to choose how much younger she'll get. ...All right then, let's go with..."