At this point is where I committed the teaching mistake for the week.
For the first two days of the week, after the ideation session, I divided the students to work individually on their posters. In retrospect, this was a bad call. The momentum that I had gained with the office and ideation exercises was suddenly completely lost. Students still made posters, and actually some very good ones too, but the energy level dropped substantially.
Having gone from group to individual was not a good call. For the last three days of the exercise I changed it a bit… and had them work as teams, which not only kept the energy levels going, but also produced larger scale work.