You need to stop using the term "cisgender." This term is very offensive to me and others. It is a slur used to describe a Heterosexual. Which is the term I prefer. You would think on an anti-harassment training. You wouldn't use an offensive term, while explaining the way people can be harassed. Within the training the guidelines that was mentioned were. 1: Don't force your opinions or social expectations about gender, 2: Be conscientious and respectful, 3: Avoid assumptions and stereotyping individuals.
I believe you missed the point completely within the training. When you showed the two (assuming gender) women talking outside the room while the (assuming gender) man was doing whatever he was doing. The training projected that those two persons outside the room were projecting insecurities and possibly fear about what the person in the room was doing. When it could just be in fact that the two persons outside the room found it annoying that they must continue working when their co-worker gets to relax and do whatever on company time or within the work day. Just like when smokers back in the day would go on a smoke brake several times a day while the non-smokers had to keep working.