Ok, once again, I've got a LOT to say.
The First Spell
It was very tempting to add light effects to the last two panels as a bit of stylistic "look at me, I know how to use the gradient tool" flair, but resisted. This is intended to be somewhat demonstrative of how the spell works, and I wanted to make it apparent that the only physical evidence of the spell, beyond the obvious changing of clothes, is a mysterious, quick gust of wind.
And yes, that means there's no transition from the old clothes and the new. No glowing, no morphing, and definitely no brief moment of nudity. New clothes appear with a bit of upward wind, and that's it.
I never wanted this to be the same ladies room as the one previously seen at South, but only because I have a general layout of the school in my mind, and that one isn't the closest to where they'd hang out in the morning.
All the same, I figured the two bathrooms would look the same. I don't feel a big need to have bathroom variety in my comics. The reason this bathroom is green, however, is that the horrid pink of the previous bathroom didn't have satisfactory contrast with Nanase. Also, this sort of green is sort of sickly, and I find that fitting for a public restroom.
That vent looks satisfactory to me, but it also has a weird visual effect if you look at it. It was weirding me out while I was making the comic.
Cutting to the Chase
There was originally another page before this one in my script. It had Grace and Justin, and was nothing more than a transition comic without any memorable jokes or content.
The purpose of that cut page? Establishing that Nanase was going to show Ellen her magic in the ladies room, and confirm that Nanase learned more than one new spell. Instead, Ellen establishes both in the first panel of this comic. I'm just glad I realized I could do that before drawing the cut page.
For anyone thinking "Dude, I want to see the lost comic", I'm reminded me of when they release deleted scenes on DVDs. I tend to get excited about the new(ish) content, but quickly realize that with only a few exceptions, things are usually cut with good reason.