EDIT: Hanma is basically saying "they're cute" in the last panel. Sorry, momentarily took for granted that everyone would understand that.
Susan's not wrong. You'd need a ridiculously narrow handkerchief to get a toga that short (folding to get that result would make it way too thick on a shrunken figure).
Hanma's not wrong either, though, at least not if we're talking cartoon characters, and so long as we're dealing with responsible camera angles.
WRITER'S BLOCK OF DOOM
I had such writer's block for this comic, One of the annoying things about writer's block is, once you've worked past it, what you've written feels obvious in retrospect.
"Well, obviously, 1:7 scale was chosen for a reason that's relevant to Hanma, but the toga doesn't have anime relevance, and was instead suggested by Susan, who has wound up seeing a lot of movies and who has seen the likes of Dr. Cyclops and whatnot, and she logically assumed it would cover more of Ashley's legs. OBVIOUSLY."
Dr. Cyclops is a 1940 horror movie that was nominated for an Academy Award for its special effects and involves people being shrunk. I have the movie on DVD, but haven't actually seen it yet. Ashley's Toga does not match what's worn by the shrunken people in the movie, but I was considering referencing it.
I'm happier having gone with something different and more unique, but that movie gets some credit for inspiration nonetheless.
Anyway, not wishing to spoil, but yes, you can reasonably expect to get a size comparison between shrunk Ashley and pet kitty Rhoda later this week.