The size of the monologo.svg at message/output/popup/templates/notification_area_content_area_header.mustache is not specified.

Moodle docs state that the format should be 24x24 (https://docs.moodle.org/dev/Moodle_icons).
This creates the possibility of a very unpleasant display of the image where it extends far into the content of notifications.
For example, mod_questionnaire currently has an image larger than 24x24, and the image reaches far into the message.

I have already filed an issue for the mod_questionnaire plugin. Furthermore, it is necessary to enforce the image size from the Moodle side at this point.

https://github.com/moodle/moodle/blob/master/theme/boost/scss/moodle/message.scss#L234
Probably, the CSS selector should have been .image-container img.

Steps to reprudouce:

• Create a questionnaire-activity and activate: "Send submission notifications" -> "Notification only"
• Create a question
• Make a submission with a different account
• The account which created the activity (must be trainer in the course) gets a notification
• Click on the Notification bell and chose "See all"
  you will be forwardet to the Notification page: "<ROOT>/message/output/popup/notifications.php"
• Click on the questionnaire notification
  -> The monologo image is displayed far to big

This is a follow-up issue to: MDL-77869