Matt,
I have advanced a little bit regarding this issue.
1. I have found the option in the program settings it is "Online Metadata" > Lookup cover art for files that have no cover art at playback time. I had this setting to OFF, but it was showing the cover art for networked FLAC files even when this setting was off of course this is obvious because they are embedded in the file, only ISO files didn't show the cover art.
2. So now I have the cover art shown in the "Playing Now" BUT I would like to use the MCWS command to retrieve them.
This is the procedure that I am doing in order to get the image file:
1. By using the MCWS command
http://localhost:52199/MCWS/v1/Playback/Info?Zone=-1 and retrieving the filed
<Item Name="ImageURL">MCWS/v1/File/GetImage?File=1061</Item> for example.
2. After I got the image link MCWS/v1/File/GetImage?File=1061 I am running the MCWS command
http://localhost:52199/MCWS/v1/File/GetImage?File=1061 in order to retreive the image but by running this command I got "The website cannot display the page" (this is the result that I have in Internet explorer after running this command). Please note that if I am doing the same above procedure for FLAC files that resides in a network share then I can get the image (shown in Internet Explorer for example)