For the most part Reinhard was just sitting almost perfectly still in his chair, head resting in his left hand, with the left elbow resting on the table in turn. His eyes were loosely pointed forward, although visibly not focussed on anything; Reinhard was bored. He did like his free time, but right now, he had none, as he couldn't really leave the classroom without breaking the rules.
At most he would bend the rules to their limit, but he knew he shouldn't break them, at least not if it was avoidable; it was easier to cope with the rules, than with the punishments for breaking them repeatedly. If nobody could possibly find out, it certainly would be a different story, but any teacher could enter or pass by the classroom at any moment currently.
Boredom by itself wasn't too bad though, as an only-child one knows how to keep oneself occupied at any time in any situation.

Still, Reinhard had kept his belongings, including his noble arm, in his general field of view, simply as a precaution, considering what the students around him were doing.