Malfoy was startled and nearly fell back, but he was a soldier at heart. Even if he was scared, he would fight, not run! Since he was exposed, he attacked the mirror, yet his attack bounced off it like it was nothing.
The next second, everything returned to normal. Molfoy was standing in the bathroom, and his reflection was absolutely normal. There was no frozen statue, and there was no shadowy wolf staring at him.
Malfoy snorted, and was about to turn away when he noticed something in the reflection. There was a window showing the outside of the castle, and outside he saw Kaemon standing on the ramparts, watching three armies fight.