Kyatric - I'm getting those numbers from the "viewers" count under the Twitch video feed. Assuming their numbers are accurate, the first week there were 60+ viewers and last week about 40 at the max.
IRC was more active because we were told in the first week not to bother posting questions in Twitch and to go to IRC instead.
Perhaps you could ask for a roll call in Twitch chat to double verify how many viewers are actually there.
With over 400 signups for the class, 40-60 attendees seems more accurate than the 15 or so in IRC.