In the media gallery, there is a place for both a photo caption and a description. For the past 6 months, we’ve displayed the photos in a gallery, and when we clicked on the image, we were able to see the description there. (This is in the “waiting children” section of our blog–on the right sidebar).
Today, I went in to edit the gallery, and the descriptions can no longer be viewed. The only thing I did in the “gallery settings” was to click link thumbnails to “attachment page” instead of “image file”. I didn’t know what that change would do, but when I saw the descriptions had disappeared, I changed it back to link to the “image file”. Still can’t see the descriptions.