Understandably, there is confusion about what to react to when. My apologies.
Basic rule: look at the calendar, and react to the topic listed for that day. If you see a posted short for the topic, react to that before class. If you don't, you can either react to notes, or wait until class and react to lecture.
Today: more ray tracing. React to lecture.
Future: to help I'll post reminders before class whether or not there is a short.