No, it really, really isn't. You need to show you are 'teaching' and they are 'learning'. Choose a year 2 LO from the late summer term and then plan a lesson around that. You need a mental oral, an activity, that you end with a plenary. I would say a 5 min starter, 5-10min teaching input for activity, 10-15 min activity (you with a group), 5 min summary/plenary. This part of the interview is to see how good you are at teaching, not how well you can keep children occupied for half an hour. Plan it well and properly, including what you would do to move on if you had more time or another lesson to do so. Read their most recent ofsted, read everything on the school website, read everything they have sent you. Go there feeling really familiar with the school. Best of Luck!