There are two things I would guess this would mean:
(1) since it’s a good chunk of time, bring a layer or two to make sure that you can deal with whatever temperature the place is.
(2) make sure you can move in what you wear. So, nothing too tight…nothing to short or too low. I would say put on the outfit, squat, and do a high kick or two. If you can do that…you’re all good.
But what @josie said is spot on, too. They might very well be trying to see who you are by what you wear. When you layer, make sure you wouldn’t mind being seen in each by a superior in an office context (i.e., if it feels borderline, it’s wrong).
I wouldn’t stress. A decent pair of pants (again, not too tight), a nice blouse, sweater, and blazer combo will probably do it.
PS – It would be hilarious if the “testing on vocabulary and logic” is partially…“How will she approach the question of “comfortable.” ;-)