BTW, I just found in the docs how we can change the default presentation.
Change the default presentationAnchor link for: change the default presentation
When a new meeting starts, BigBlueButton displays a default presentation. The file for the default presentation is located in /var/www/bigbluebutton-default/default.pdf . You can replace the contents of this file with your presentation. Whenever a meeting is created, BigBlueButton will automatically load, convert, and display this presentation for all users.
Alternatively, you can change the global default by editing /usr/share/bbb-web/WEB-INF/classes/bigbluebutton.properties and changing the URL for beans.presentationService.defaultUploadedPresentation .
# Default Uploaded presentation file
beans.presentationService.defaultUploadedPresentation=${bigbluebutton.web.serverURL}/default.pdf
You’ll need to restart BigBlueButton after the change with sudo bbb-conf --restart .
If you want to specify the default presentation for a given meeting, you can also pass a URL to the presentation as part of the create meeting API call.
I made a basic slide set here. I’m not happy with the colours, i.e. I tried to make the icons change from blue to green, but I’m clearly no magician with The Gimp or other design tools 