Right-click the icon of the artwork. Choose the alternative Download media.
In the dialogue box that opens you can see which files that are available for you. If you need only some of the files, untick the tick boxes of the files you don't need (it will probably speed up the download).
The formats you can download are dependent on your role and permissions. If you require a file format that isn't there, request a higher permission set from your Cway admin.