You can configure how the link to the agenda will look in the event, when seen in a page or a quick link. This includes the icon used, the title and the subtitle.
To do so, in the Sessions module, in the Preferences tab, go to the Content editor > Link appearance option:
Here you can configure the following:
This is the icon associated to the agenda link. You can upload your own or select one from the list.
This is the main title of the link. You can select a label from the list or create your own (along with any corresponding translations).
This is the subtitle of the link (same approach can be used here as for the title).