Purpose of widget preview in wearable

What is the purpose of the preview image in a wearable widget?  In other words, when is it shown?


I assumed that when adding a widget to the home screen the ICON would be shown in the list of available widgets....but I can't find any reference to this topic, or the required size of the preview image.


Should the preview be identical to the icon?  (Then why have 2 images)

Edited by: Michelle Dupuis on 22 Aug, 2019