He sets back in his stance, pleased with the hit, but not because he managed to hit her. It was because now she was getting a taste of what it was like to be in a real fight. Vegeta's confident that the blow he'd just dealt wasn't going to end it for her, but rather send a rude wake up call on how to defend herself a little better. Smiling, he calls out to her-

"You've got to be a bit quicker than that! That wasn't even hard. Now come on. I gave you a challenge and you've yet to rise to meet the occasion. Just because I'm your dear old dad doesn't mean you should be holding back."