In the past we've heard feedback from clients who want to display the latest thumbnail of a linked Entity from the Entity's thumbnail field. For example, for a Shot you might want to see the Latest Version linked to that Shot as opposed to manually updating the Thumbnail field for the Shot.
We're looking at supporting the ability to customize the Thumbnail field in the UI to be a Query of a linked Entity. Please add your support to this ticket if you'd like to see this feature released in the future.