Each of the group has received one of 23 topics. You will have 15 minutes to present to the rest of the group, without lecturing.
From what I understand, at the end of the 15 minutes, everyone should have learned something of the topic you received. You have to move your knowledge to the rest, in a memorable way, at the best of your abilities.
If you don’t understand it like that, please discuss here or in the forum.