1. Go to Dashboard --> Advanced --> Customization script
2. Add the script as shown below.
// show sponsor image in waiting room //
$("#page-content-wrapper > div.content > div.panel.panel-default.workshop-waiting-room > div.panel-body").append('</br><img src="https://i.imgur.com/iY5JpTg.png" style="width:50%; height:50%"></img>');
3. Change the Imgur link [https://i.imgur.com/iY5JpTg.png] in the script above in your own Imgur link address, as shown below.
