It's a range exam, so they have a circle some distance away from the targets. She's allowed to lean over the circle, but not touch the ground beyond that. She just took it to the extreme and "leaned" (jumped) onto the targets and only then touched the ground after the targets were destroyed, as that is allowed.
I see what is happening, there is a band of a given width that is in a circle around the targets and it seems like he means “Stand inside of this area and then cast but don’t leave the bounds of this band.” That makes sense, but letting her do the run up is the crux of it being a bit cheap.
I thought she gonna make snowball out of the ground and use it as hand cannon ball, or swing her arm so hard it creates hurricane, or spit sniper, or blow it with freezing monsoon. Yeah, well, rider kick is also good.