A description can be added and metadata tagged when a collection is created, when adding files to an existing collection or by clicking a file with a collection.
When creating a new collection or adding files to an existing collection, you to add information to all the files being added and to individual files being added.
To edit information for a file within a collection, click the pencil icon while hovering over the image.
To edit information for a file from All Files, click the pencil icon. You can also click the file, then click the pencil icon to edit information.