ObjectPicker with custom resultTemplate

I would like to customize the look of object picker options, so that they display an additional icon (e.g. <i class="fa fw fa-exclamation"></i>) if a specific condition is met.

According to the documentation, you can specify a custom mustache template for the resultTemplate attribute :
https://docs.preside.org/reference/systemformcontrols/objectPicker.html#arguments

Unfortunately I don’t have any idea what the template should look like in order to append an icon to the option text.

Can anyone point me in the right direction, please?