Hi,
In a default recording the presented content (desktop, PPT, etc) will be shown on the right side in the final video. Chat and Participants video will be shown on the left side.
After recording the meeting you can open the Recording Manager and select what should be included in your final video. You can select to include on or multiple of the options Audio, Participants video, Panorama video, Instant message and Presented content.
- Open Lync and click Tools, Recording Manager.
- Highlight a recording and click Publish.
- Click Options and uncheck any of the content that you don’t want to keep.
- Type a new name for your recording in the Recording file name box.
- To change the location of the recording, click Browse next to the Save to box, then go to the folder where you want to save the video.
If you don't want the attendees to be active in the meeting you can block this in the meeting by making everyone an attendee and the block video and IM.
https://support.office.com/en-us/article/Change-participant-settings-for-Skype-for-Business-meetings-9175e297-de5f-43b2-8e0f-85cc05e24986
