Good morning 
,
Is there a reason why we cannot list in the “COLUMN TYPE” : Reference
a field that is an attachment, I would like to be able to choose from the “logo” field instead of the title .
Thanks
Maybe that can be allowed. I think the limitation today is that a Reference column can only display plain text (not even colors). But there is a workaround, at least for viewing.
You can add a formula column with the formula $shop.logo, and set its type to Attachment. That should allow you to see the logo of the linked record.