Drag-drop a .psd in DAM creates a "File" instead of "Picture"

All is in the title.

• Have a photoshop file
• Drag-drop it in the DAM interface
• You see the thumbnail but that's all, because nuxeo created a "File", not a "Picture"

If you click the "New Asset" button, explicitely ask for a picture and upload the file, all is good, you have the preview, the annotation, etc.

NOTE: The same occurs if you drag-drop in DM