What are the format for these files ?
When making the preview of a document we need to specify the format of the document. In this example we want to preview a photo, so the format is image : http://localhost:8080/nuxeo/site/api/v1/repo/default/id/23d871d2-052a-4f58-8f90-4b07c5a074ea/@blob/file:content/@preview/image
But what are the format for these file extensions : .mp4, .docx, .xlsx ?
The name after
@preview/ corresponds to the converter name which is used for the main file, so it depends on the converter.