As storing content of an asset in a Sylius Attribute is difficult, and we don't want to duplicate his data everywhere, a new table stores the content of each asset.
This task is done by executing the import assets command.
The value is stored as json inside an "url" node in the asset content column.
The attribute configuration is stored as normal attribute. The configuration contains all the available values and their translations.
This task is done while importing product models.
Currently, we only support asset attribute of type "media_link". We only store the asset code inside the value, and we expose the assets node inside the product.