I use a 30-seconds-of-work horribly-hacked Stylus setting to make it a blue dot that can expand on hover:

@-moz-document regexp(".") { / Insert code here... */ #credential_picker_container { width: fit-content !important; height: fit-content !important; } iframe[src^="https://accounts.google.com/gsi/iframe/select"] { width: 10px !important; height: 10px !important; border-radius: 50% !important; background-color:blue !important; } iframe[src^="https://accounts.google.com/gsi/iframe/select"]:hover { width: 300px !important; height: 300px !important; border-radius: 0 !important; } }