That dark gray box is where the productMusic media manager wants to display. I think you need to do something about that product...
P.S. - You said "it's in my dvd folder"; there is no reason for you to be using that subfolder, or any subfolder below /images/, unless you need to organize a lot of images and having them all in one folder is confusing. (THis does not include /medium/ and /large/ - you need them in any case.)
The tutorial mentions the dvd folder, so I think a lot of people follow it blindly. It should mention that that is optional.




