The most important point to note is that you are preparing a demonstration NOT a presentation or a paper. The context of the Machine Intelligence (MI) competition is that an audience (of AI practitioners) vote on which system demonstrates the best or most progress towards Machine Intelligence. The audience is asked to consider the demonstration alone and definitely NOT the technology behind it.
With this in mind, it is clear that MOST of the 10 - 15 minutes allowed for the demonstration should be a REAL demonstration and not a talk about it or a series of slides about it. Many demonstrations from previous competitions have involved people from the audience to try things out, however, it is not always easy to get a volunteer.
A useful model to consider when allocating time for your demonstration would be:
2 Minutes (maximum) to introduce the team and their work.
4 Minutes (maximum) to explain what the demonstration should achieve.
9 Minutes (minimum) for the actual demonstration including audience involvement time if any.
You have a greater chance of winning based on the demonstration than on talking about it. Demonstration is in keeping with the spirit of this competition. Hopefully it works well; sometimes it does not, that is all part of the competition.
Good Luck and thank you for participating in the competition. Everyone understands that presentation is a lot easier than demonstration so simply plan well and do the best you can.