The compact view supports defining transformations (image size, fill, mirroring, ...) while selecting the media item. To be able to use that feature, a few configuration steps must be completed.
Configure the Entity browser
First we need to configure the Entity Browser, so that it uses the single file compact view variant.
To edit Webdam entity browser, go to Configuration > Content authoring > Entity browser
Choose the Entity Browser to modify and click Edit.
Go to Widget Settings
Check the `Use single file selection mode` checkbox.
Save your modifications.
Display configuration
Now we need to configure the display for the Webdam media type.
Edit the Webdam Media Entity.
Select the option "Webdam (Image)" in the Webdam ID dropdown menu.
Click on the gear icon to access the parameters.
Then I check the checkbox ` Use user-selected asset transformations if available` and press `Update`
Press `Save` at the bottom of the page.
You will now be able to use transformations in the Asset browser
Caveats
This gives editors (or other roles that can use Webdam media) full control over the image presentation. This means that images might spill out of page boundaries or not fall into other guidelines.
The ability to opt-in to this feature per view mode allows to limit it to certain sections of a page, for example allow control over full images in content but not teaser images.