Reduce the cognitive load on your users by adding icons to each of their choices in choice resources. Icons convey information at a glance, reducing the amount of text users must read and process. Choice resources with icons can only be used in Choice Lookup and Visual Picker components. Additionally, these choice resources must be of the text data type
Where: This change applies to Lightning Experience, Salesforce Classic (not available in all orgs), in Essentials, Professional, Enterprise, Performance, Unlimited, and Developer editions
How: If you want to add an icon to a choice resource, click Choose Icon under Customize User Interface in the New Resource window

Select an icon from the available Utility, Doctype, or Standard Salesforce Lightning Design System icons. You can also search for specific icons by using the search bar

Use the choice resource in screen components, such as Choice Lookup or Visual Picker, and see the choice label with icons at run time
