I see it was the blue microphone on this video.

mic-blue.svg
related object :
T247860

@Seb35 do you have news about this? It happened since the re-opening of the website and it is quite a crucial detail
The file seems to be located here: https://github.com/lingua-libre/RecordWizard/blob/master/icons/mic-blue.svg

An important point (I think I wrote it somewhere already but I double here to be sure it's not lost) :

• it's the blue mic when recording an audio
• it's the blue hands when recording a video (for sign language, icon is https://github.com/lingua-libre/RecordWizard/blob/master/icons/hands-blue.svg I think)

The message string should contain a <i></i>.
The RecordWizard's stylesheets/ext.studio.css then handle the rest.

Content moved to twin issue.