Request: use a specific media as thumbnail

[symac]

Currently there are two options if you want to use a specific media attached to an item as the thumbnail for this item. Let's imagine you have an item for a book with a jpg per page :

• page0001.jpg
• page0002.jpg
• page0003.jpg
• page0004.jpg

As it is often the case with old books, let's assume the first pages are just a cover that is meaningless and a blank page and you want the page0003.jpg to be used as the thumbnail for this item.

From what I understand there are currently two options to do this:

• reorder the list of media attached to the item so that page0003.jpg becomes the first one in the list → it becomes unclear in backoffice why this order has been chosen;
• upload a copy of page0003.jpg as an asset → duplicating the file on the server does not seem a best practice;

It would be great, on the thumbnail tab when editing an item to be able, in addition to asset upload, to be able to choose from a media already attached to the item. From what I have seen in the database it's not obvious to change this behavior but I believe it would improve this thumbnail function.