It turns out that I can allow comments for the album and for individual photos of the backgrounds :) You need to be viewing the photo (not just the gallery view) to add a comment for that photo.
Feel free to add comments to the individual photos about what you like and don't like. Once again, the photos are here. Thanks very much for your help - I really appreciate it.
Edit: Photos have been rearranged so that the earrings are in columns. Thanks for the suggestions :)